=Paper= {{Paper |id=Vol-3878/93_main_long |storemode=property |title=Morphological vs. Lexical Antonyms in Italian: A Computational Study on Lexical Competition |pdfUrl=https://ceur-ws.org/Vol-3878/93_main_long.pdf |volume=Vol-3878 |authors=Martina Saccomando,Andrea Zaninello,Francesca Masini |dblpUrl=https://dblp.org/rec/conf/clic-it/SaccomandoZM24 }} ==Morphological vs. Lexical Antonyms in Italian: A Computational Study on Lexical Competition== https://ceur-ws.org/Vol-3878/93_main_long.pdf
                                Morphological vs. Lexical Antonyms in Italian:
                                A Computational Study on Lexical Competition
                                Martina Saccomando1,∗ , Andrea Zaninello2 and Francesca Masini1
                                1
                                    Alma Mater Studiorum - University of Bologna, Bologna (Italia)
                                2
                                    Fondazione Bruno Kessler, Trento; Free University of Bozen-Bolzano (Italy)


                                                 Abstract
                                                In this paper, we examine the competition between pairs of adjectives in Italian that are antonyms of the same term: one is a
                                                “morphological antonym” formed by negative prefixation, the other is a “lexical antonym” with no morphological relationship
                                                with the term in question. We consider pairs of adjectives that are reported as antonyms in lexicographic resources and
                                                extract the nouns that can be modified by both adjectives from a large corpus. We select a set of 8 nouns for each pair
                                                that present higher, lower, and comparable frequencies combined with each antonym respectively and then we perform
                                                two experiments with a LLM. Firstly, we perform experiments for masked-token prediction of the adjective, to study the
                                                correlation between prediction accuracy and the frequency of the noun-antonym pair. Secondly, we perform a polarity-flip
                                                experiment with a multilingual LLM, asking to change the adjective into its positive counterpart. Our results point to the
                                                conclusion that the lexical antonym seems to have a narrower lexical coverage and scope than the morphological antonym.

                                                 Keywords
                                                 Antonymy, Morphological antonyms, Lexical antonyms, Competition, Corpus analysis, Large language model, Token
                                                 prediction, Polarity flip, Italian



                                1. Introduction                                                                                felice                                                  infelice

                                Antonymy is the semantic relationship between terms
                                                                                                                                                                                       triste
                                with opposite meanings. In their canonical form, two
                                antonyms’ meanings can be represented as the poles of a
                                semantic continuum [1] where one term has a “positive”                                 Figure 1: Two possible antonyms, one morphological, one
                                semantic value, the other a “negative” one [2].                                        lexical, for the same word.
                                   In Italian, given a word (e.g., the adjective felice
                                ‘happy’), antonyms can either be realized via prefixa-
                                tion of that word (e.g., infelice ‘unhappy’) or through                                                          lexical antonyms; explicitly in the case of morphological
                                an independent lexeme (e.g., triste ‘sad’). In our work,                                                         antonyms, by adding a prefix with a negative, contra-
                                we refer to these types of antonyms as morphological                                                             dicting value. Considering their different morphological
                                antonym and lexical antonym, respectively. A word in                                                             structure, one possible hypothesis on their lexical com-
                                the lexicon may have both a morphological and a lexical                                                          petition is that the morphological antonym has a more
                                antonym, only one of them, or neither. In this paper, we                                                         restricted semantics, representing the negation of the se-
                                are interested in triplets of adjectives where a positive                                                        mantics of its adjectival base, while the lexical antonym
                                adjective (e.g., felice) presents two possible antonyms (or                                                      has a broader semantic coverage, as it is morphologically
                                “co-antonyms”), one formed morphologically by prefix-                                                            independent from its positive counterpart (see Section
                                ation (e.g., infelice), one morphologically independent                                                          3).
                                (e.g., triste) (Figure 1).                                                                                           To the best of our knowledge, despite the wealth of
                                   In this paper, we are interested in studying the factors                                                      literature on antonyms (Section 2), there is no empirical
                                that govern the selection of the morphological antonym                                                           in-depth study that investigates the competition between
                                vs. the lexical one. These two types of antonyms express                                                         morphological and lexical antonyms in single languages,
                                “negative” semantics with respect to the opposite, “pos-                                                         including Italian. Studies on antonyms do identify the
                                itive” term in different ways: implicitly in the case of                                                         two types of antonyms but generally do not address the
                                                                                                                                                 factors influencing the preference for one type over the
                                CLiC-it 2024: Tenth Italian Conference on Computational Linguistics, other intralinguistically.
                                Dec 04 — 06, 2024, Pisa, Italy                                                                                       This study investigates the competition between these
                                ∗
                                     Corresponding author.                                                                                       two types of antonyms by firstly studying their distri-
                                Envelope-Open martina.saccomando@studio.unibo.it (M. Saccomando);                                                bution in corpora (Section 5.1); secondly, by testing the
                                azaninello@fbk.eu (A. Zaninello); francesca.masini@unibo.it
                                (F. Masini)                                                                                                      ability of a native-Italian language model to predict them
                                                    © 2024 Copyright for this paper by its authors. Use permitted under Creative Commons License in a masked-token prediction task (Section 5.2); and, fi-
                                                    Attribution 4.0 International (CC BY 4.0).




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nally, by performing a substitutability task within the        only one of the antonyms possesses, preventing their full
same context by switching the polarity of the context sen-     synonymy and interchangeability.
tence with a SOTA multilingual LLM, in order to study              Justeson and Katz [12] take a different approach. Using
when the adjective is switched to the positive un-prefixed     the Brown Corpus and Deese’s antonym dataset, they
adjective or to another, positive but morphologically un-      were among the first to study antonymy based on a cor-
related one (Section 5.3).                                     pus. They found that antonymic terms co-occur more
                                                               frequently than expected, confirming a syntagmatic rela-
                                                               tionship between them (in addition to the paradigmatic
2. Background                                                  one). This syntagmatic relationship was confirmed by
                                                               a more extensive work carried out in subsequent years:
Whereas the exploration of the competition between mor-
                                                               Jones [11] collected 56 antonym pairs, analyzing jour-
phological and lexical antonyms, addressed in this paper,
                                                               nalistic texts, to identify eight discursive functions of
has not gained much attention so far, the literature on
                                                               antonym co-occurrence.
antonymy in general is abundant, especially in relation
                                                                   A study that does address the competition between
to the English language.
                                                               forms is Aina et al. [13], who studied syntactically
   A term’s antonym is related to it according to three
                                                               negated adjectives and morphological antonyms (e.g.,
main characteristics: polarity, gradability and canon-
                                                               not happy vs unhappy, respectively). Using distributional
icity. The first two characteristics refer to the position-
                                                               semantics they found that a syntactically negated ad-
ing of the two antonymic terms w.r.t. the two poles
                                                               jective is more similar to the positive adjective than to
(polarity) of a graded (gradability) scale [3], along
                                                               its lexical antonym. Additionally, they show that the
which free positions can be occupied by other similar
                                                               morphological antonym is less similar to its lexical base
but differently graded terms. The scale is based on a spe-
                                                               compared to the similarity between a negated adjective
cific property that the two terms share. For example, in
                                                               and its non-negated counterpart.
the pair long-short, the two antonyms share the property
                                                                   Last but not least, a very recent typological study [14]
of “length”, defining the start and end of an axis whose
                                                               examines 37 antonym pairs across 55 languages, focusing
poles are defined by two terms, with long representing
                                                               on antonym formation. When a derived form is attested,
the “unmarked” base term of the opposition (this is why
                                                               it typically applies to the member of the pair with lower
we ask for “how long” rather than “how short” something
                                                               valence or lesser magnitude. Antonyms related to core
would last [4]).
                                                               property concepts (dimension, age, value, color) tend to
   However, there are cases where antonymic pairs
                                                               be expressed through distinct lexical forms (resulting in
are formed with potentially competiting antonyms,
                                                               lexical antonyms), while those related to peripheral prop-
like friendly-unfrendly vs. friendly-hostile: friendly-
                                                               erty concepts (physical property, human property, speed)
unfriendly is placed on a scale that defines a greater or
                                                               are generally encoded using derived forms (namely mor-
lesser degree (gradability) of a property, while friendly-
                                                               phological antonyms). Although the study is insightful
hostile are certainly in opposition but belong to two scales
                                                               and inspiring in a number of ways, the specific question
of incompatible properties. In terms of their gradability,
                                                               of which reasons underlie the preference for lexical or
therefore, it seems that the morphological antonym is
                                                               morphological forms in a single language remains unan-
“more gradable” than the lexical one.
                                                               swered.
   Canonicity, according to Paradis and Willners [5],
defines two semantically related and conventionalized
terms as a pair in the language. It is a gradual property      3. Morphological vs. Lexical
and can be possessed to a greater or lesser extent. A
high degree of canonicity translates into a high degree           Antonyms
of semantic-lexical embedding in memory and leads to
                                                               A morphological antonym (e.g., inattivo ‘inactive’
conventionalization in usage.
                                                               from attivo ‘active’) is immediately recognizable as a
   Psycholinguistic studies also suggest that canonical
                                                               negative term due to the presence of the negative prefix
antonyms derive from the speakers’ experience with the
                                                               un- ‘in-/un-’, while the nature of the opposition is less
language: the two terms are inseparable, one elicits the
                                                               immediate with a lexical antonym (e.g., passivo ‘pas-
other [6, 7, 8, 9, 10]. When a term has two structurally
                                                               sive’), because one has to identify the property shared by
different but semantically similar antonyms (Figure 1),
                                                               the two opposing terms.
canonicity is influenced by factors such as learned pref-
                                                                  Moreover, these two ways of forming an antonym
erence for specific pairings, the speaker’s familiarity due
                                                               from the same term create an asymmetric system: while
to exposure, and different nuances of meaning [11]. Out
                                                               one of the two terms in lexical opposition (e.g., attivo
of context, the antonyms may appear equivalent, but
                                                               ‘active’) has its morphological antonym (e.g., inattivo ‘in-
within context, a specific meaning may be activated that
active’), the other term (e.g., passivo ‘passive’) does not     a wider range of ways of not being friendly (such as being
(e.g., *apassivo, *impassivo, ‘*unpassive’). This imbalance     aloof) whereas hostile is fairly specific” (Murphy 2003:
is due to the greater emphasis that language places on          202). So, the morphological antonym would be more
everything that requires more precise specifications [15].      polysemous, while the lexical counterpart would have
The situation is not always perfectly equivalent interlin-      a narrower scope.
guistically: for example, a form like *invero to indicate          Given these two competing hypotheses, we aim to
the opposite of vero ‘true’ is not attested in Italian, while   empirically verify:
it is possible in English (untrue).
    However, there are cases in both Italian and English              • whether the lexical antonym is more frequent
where the two competitors have different nuances: for                   than the morphological antonym;
example, infelice-triste / unhappy-sad cover different con-           • whether the morphological antonym is actually
texts in that triste and sad convey a stronger emotional                less polysemous than the lexical antonym.
meaning, while infelice and unhappy encompass certainly
                                                                In order to do this, we design a set of experiments. We
strong but less intense feelings.[16]
                                                                first select antonym pairs; we calculate their frequency
    Regarding distribution in usage, lexical antonyms
                                                                of co-occurrence with nouns to have a defined context;
are predominant for more basic meanings, supporting the
                                                                then, we perform two tasks: (i) masked-token prediction
Principle of Least Effort theorized by Zipf [17], which sug-
                                                                and (ii) polarity flip.
gests that we expect the most used concepts to be coded
with short and simple words: basic terms therefore tend
to have structurally simple antonyms even when more             4. Dataset Construction
complex morphological antonyms would be possible. For
example, for a pair like alto-basso ‘tall-short’, there is no   4.1. Antonym Pair Selection
morphological counterpart that can be associated with ei-
ther term: neither *inalto ‘*untall’ nor *inbasso ‘*unshort’    For our study, we decided to focus on adjectives, as this
exist. These are canonical antonyms referring to basic          class is the most suitable for investigating antonymy,
language concepts: in cases like this, but not exclusively,     given that it includes content words that normally ex-
preference for simpler and more immediate words blocks          press qualities. Moreover, adjectives are semantically
the potential formation of a morphological antonym.             simpler compared to other word classes as they usually
    According to Murphy [4], culturally salient concepts        describe a single property that may be or may not be
necessitate clear and concise linguistic expressions. For       present to a greater or lesser degree ( Jones et al. [1]).
this reason, lexical antonyms (e.g., passivo ‘passive’) are        Starting from 1535 adjectives of the fundamental Ital-
the most frequent choice because they require less cogni-       ian lexicon extracted from the Italian dictionary Zingarelli
tive effort to understand. Although it is possible to create    2024, we filtered 303 items marked as ‘contr.’.
new opposite terms through derivational and morpholog-             We then selected, for this pilot study, 5 adjectives with
ical processes with speaker’s creativity, this option is less   the following properties: they needed to be adjectives
commonly employed in this context, as it is perceived as        with both a morphological and a lexical antonym; they
a deviation from the linguistic norm.                           needed to be maximally interchangeable in different con-
    The competition between the two terms of the                texts.1
antonym pair, i.e., the situation in which the usage con-          Finally, we created our initial dataset by pairing each
text of both terms is nearly the same and allowing for a        adjective with its corresponding morphological antonym
certain degree of substitutability, is still debated.           and a possible lexical antonym.
    According to one hypothesis, since the morphological           The morphological antonym was formed by using one
antonym is the “perfect” negation of a specific lexical         of the three possible prefixes productively used in Italian
base, it should occur in more restricted contexts (i.e., a      to create antonyms, namely: dis-, s-, in- [20]2 .
subset of the contexts of its positive counterpart) and            The lexical antonym was chosen randomly among all
should therefore have a narrower semantics (cf. [18,            possible options, taking into account synonymy with the
19, 15]). So, morphological antonyms would be less              morphological antonym and semantic neutrality. This
polysemous. On the other hand, the lexical antonym,             means that the lexical antonyms were selected to be ide-
not sharing identical lexical properties with the opposed       ally substitutable with the morphological ones in as many
term, should occur in broader contexts and thus be more         contexts as possible, and roughly possessing the same
polysemous.                                                     1
                                                                  The admittedly limited size of the dataset is due to the exploratory
    However, Murphy [4], examining the English triple             nature of our study.
friendly-unfriendly-hostile, notes that “The two antonyms       2
                                                                  The prefix in- is the most productive and the most widespread. It
are hardly equivalent, though, since unfriendly describes         often adapts phonetically to the bases it attaches to, forming the
                                                                  allomorphs im-, ir-, and il- via assimilation [20].
number of senses according to the dictionary (cf. Table 2). 4.3. Lexical Context Definition and
The synonymy between the two types of antonyms was                     Example-Sentence Extraction
further confirmed using Il grande dizionario dei Sinonimi
e dei Contrari, Zingarelli 2013 [21].                          Subsequently, for each antonym pair, eight nouns with
   Summing up, the antonym pairs examined are:                 different co-occurrence frequencies were selected. Specif-
                                                               ically, we considered both nouns that typically occur with
      • infelice ‘unhappy’ - triste ‘sad’                      one of the antonyms (e.g., matrimonio infelice), falling
      • impreciso ‘imprecise’ - approssimativo ‘approximative’ within the domain of collocations, and (more generic)
      • scorretto ‘incorrect’- sbagliato ‘wrong’               nouns whose co-occurrence frequencies with the lexical
      • imprudente ‘imprudent’ - avventato ‘reckless’          and the morphological antonym are very similar (e.g.,
      • insufficiente ‘insufficient’ - scarso ‘scant’          donna infelice and donna triste) (cf. Table 1).
resulting in 5 triplets (base, morph_ant, lex_ant).                          Noun + Adjective                                Frequency
                                                                             matrimonio infelice ‘unhappy marriage’             886
4.2. Corpus-based Analysis                                                   matrimonio triste ‘sad marriage’                    24
                                                                             donna infelice ‘unhappy woman’                     325
We analyzed the occurrences of the selected adjectives                       donna triste ‘sad marriage’                        316
with nouns in the itTenTen20 corpus, a large web corpus
                                                                       Table 1
of written Italian, searched through the SketchEngine
                                                                       Differences between high and low frequency name+adjective
platform https://www.sketchengine.eu/.
                                                                       co-occurrences
   The analysis of the occurrences highlighted that the
two types of antonyms display partially different collo-
cational preferences (see Appendix A, Table 3).                 The latter case is especially interesting for our current
   Overall, we can split the antonymic adjective-noun        purposes, as it represents possible ground for “compe-
couples in two groups according to whether the co-           tition”, namely a situation where the context of use is
occurrence is:                                               nearly the same and allows for a certain substitutability
                                                             between the two terms of the antonym pair.4
     • (i) polarization towards one of the two ad-              After defining the noun list, for each noun we ran-
       jectives: in these cases, we can speak of fairly domly selected 10 sentences containing the noun fol-
       stable distributional preferences, falling within lowed by the morphological antonym and ten sentences
       the realm of collocations or idiomaticity (e.g., mat- containing the same noun followed by the corresponding
       rimonio preferably selecting infelice rather than lexical antonym from itTenTen20. This was done for all
       triste);                                              eight nouns and for all five antonym pairs, resulting in a
     • (ii) similar with the two adjectives, indicating 800-sentence dataset.
       potential substitutability of the two antonyms in
       the same contexts (e.g., donna selecting both infe-
       lice and triste with similar relative frequencies).
                                                             5. Experiments
    Both groups are relevant to explore the context of use In Section 3 we outlined two possible hypotheses re-
of the two types of antonyms, although, for our current    garding the competition between the two terms of the
purposes, we specifically targeted the nouns in group      antonym pair and we selected the following as a working
(ii), namely nouns that occur with both adjectives, sug-   hypothesis: the morphological antonym, being formed
gesting a certain degree of competition between the two    by a negative prefix applied to a specific lexical base,
antonyms: see sentence 1, where infelice ‘unhappy’ can     would have more restricted usage contexts (possibly a
be replaced by the lexical antonym triste ‘sad’.           subset of the contexts of the lexical base), and therefore
                                                           be less polysemous than the lexical one; on the other
    1. Un ritratto preciso ma discontinuo che ci restitu- hand, the lexical antonym, not sharing morphological
       isce l’immagine di una donna infelice, umiliata, structure with the opposing term, would semantically
       affranta, ma non distrutta, non arresa alla sorte 3 cover some or all of its meanings along with other inde-
                                                           pendent meanings, resulting in broader usage contexts
                                                           and greater polysemy.
                                                             To verify this hypothesis, we performed 2 sets of exper-
                                                           iments: (i) masked-token prediction, to estimate the
3
‘A precise but fragmented portrait that gives us the image of an un-
                                                                       4
happy, humiliated, distraught woman, but not destroyed, not resigned       For a detailed view of the selected adjectives and nouns, as well as
to fate’.                                                                  their co-occurrence frequencies, see Appendix A.
probability of occurrence of one antonym or the other ac-       We used bert-base-italian-xxl-cased language model5
cording to a native Italian language model; (ii) polarity to perform a token prediction task by masking the
flip, to transform the collected sentences from a negative antonym present in each sentence. The model was asked
meaning to a positive meaning.                               to predict the probability of occurrence between the two
                                                             possible antonyms; then, we took the alternative with the
5.1. Word Senses and Lexical Variety                         highest probability according to the model as the model
                                                             prediction.
Our analysis started with the identification of adjectives
and their possible antonyms, which, as mentioned (Sec-
                                                             5.3. Polarity-flip
tion 4.1), have been chosen on the basis of their possible
substitutability within the same context. For this reason, In this task, we asked a SOTA LLM, GPT-4o, to transform
first of all, the various dictionary definitions of antonyms the sentences extracted from the dataset, both those con-
were taken into consideration. We counted how many taining the morphological antonym and those containing
senses are associated to each antonym in the Zingarelli the lexical antonym, into positive sentences.
dictionary [22], taking the number of senses reported as        We used the same prompt for all antonym pairs,
a first proxy of semantic broadness.                         parametrising the antonyms and sentences presented,
   As a second proxy, the semantic coverage of each by asking the model to flip the sentence from a negative
antonym was taken into account. We conducted an anal- sense to a positive one, always by changing the adjective
ysis of the lexical variety of each group’s context in the accompanying the target noun.6
selected sentences, by calculating the token/type ratio         We then fetched the new adjective generated by the
for each group. We report the results in Table 4. As can model, and calculated when the new, positive adjective
be seen, no relevant differences were found according to coincided with the lexical base, and when not.
these features.                                                 The rationale behind this is that the senses of an
                                                             antonym can be separated through the various positive
5.2. Masked-token Prediction                                 terms with which it can be changed. We expected that
                                                             sentences containing the morphological antonym would
According to our hypothesis, in this task we expect that be turned into positive using their lexical base more of-
the predicted antonym will have a higher prediction ac- ten than their lexical counterparts, indicating a narrower
curacy in the sentences with the highest occurrence of semantics.
the adjective with the selected words (represented by
high relative frequency). In contexts with similar fre-
quencies, we expect that accuracy should be similar for 6. Analysis and Results
both antonyms, showing a genuine competition between
the two, as the language model should not have a specific As regards the number of meanings listed in the dictio-
preference.                                                  nary for the two terms of the antonym pair (Table 2),
   We previously said that the words that form the these are almost the same, indicating that the recognized
antonym pairs can be considered synonymous. In fact, senses of each antonym alone are not decisive to de-
full synonyms are rather rare (Murphy [4], among oth- termine the selection between one or the other. As for
ers), also because languages tend to avoid synonymy by lexical variability (see Appendix B, Table 4), token/type
differentiation in terms of meaning or distribution [23]. ratio also fails to reveal a significant difference between
Therefore, the two terms of the pair are better regarded as morphological and lexical antonyms; in only three cases
near-synonyms, meaning that one term can cover almost does the token/type ratio of lexical antonyms exceed
all the meanings of the other but not all of them.           that of morphological antonyms. This seems to indicate
   To evaluate the factors that lead to the choice of one that factors other than contextual variability underlie the
antonym over the other, we decided to observe how a na- preference for one or the other.
tive Italian language model pre-trained for masked-token        Let us now consider Table 3, Appendix A. In addition to
prediction model behaves in terms of the probability of      the co-occurrences of nouns with the two antonyms, the
occurrence of an antonym in a given context. In this accuracy for the two tasks for each noun-adjective pair is
respect, see Niwa et al.[24], who used BERT to predict also provided (further divided into noun-morphological
antonyms in specific contexts: experiments on Japanese antonym and noun-lexical antonym). The distribution
slogans showed a top-1 accuracy of 29.3% and a top-10 of nouns in this table follows a specific order: nouns at
accuracy of 53.8%, with human evaluations confirming the extremes exhibit occurrence frequencies polarized
that over 85% of predicted antonyms were appropriate,       5
                                                                dbmdz/bert-base-italian-xxl-uncased
demonstrating the method’s effectiveness in capturing       6
                                                                For detailed information on the prompt used in this study, please
contextually relevant antonyms.                                 refer to the Appendix B.
                                                                                   accuracy      accuracy
                                                                                                                 polarity    polarity
                                   senses       senses      rel.freq   rel.freq   mask token    mask token
                                                                                                                   flip        flip
                                                                                  prediction    prediction
  Couple                         Exp.morf      Exp.lex     Exp.morf    Exp.lex     Exp.morf       Exp.lex       Exp.morf      Exp.lex
  infelice-triste                    4           4           0.48       0.52         0.525         0.687          0.125        0.137
  impreciso-approssimativo           2           2           0.57       0.43         0.256         0.833          0.081        0.222
  scorretto-sbagliato                3           3           0.48       0.52         0.025         0.986          0.076        0.144
  imprudente-avventato               2           1           0.43       0.57         0.437         0.637          0.012        0.075
  insufficiente-scarso               3           3           0.40       0.60         0.743         0.662          0.012        0.037


Table 2
Final experiment results. Number of senses, average of relative frequency and average of the accuracy of the two tasks: mask
token prediction and polarity flip.



towards either the lexical antonym or the morpholog-                range of senses (see, e.g., Murphy [4]).
ical antonym. Some nouns form with the adjective a                     We believe that these results, that contradict our ini-
fairly stable collocation, while other nouns form freer ex-         tial hypothesis, open up new avenues for future research
pressions. For the purposes of this study, particularly in          in this area, despite the limitations of the present study,
relation to the analysis of competition, the central nouns          which has an exploratory nature and a narrow empiri-
with similar frequencies are of greater importance.                 cal coverage. Indeed, only 5 adjectives were analyzed,
   Upon examining the occurrences and accuracy, we                  exclusively belonging to core vocabulary. Another short-
observe that the values are comparable.                             coming is that, unlike for English, there are no in-depth
   As for masked-token prediction, the consistent higher            studies on antonyms in Italian. However, we want to
values of the lexical antonym indicate higher predictabil-          stress the importance of conducting studies on languages
ity and/or higher degree of idiomaticity, which contra-             other than English to avoid the well-known Anglocentric
dicts our working hypothesis that lexical antonyms dis-             bias.
play a broader semantic coverage.                                      Hopefully, our results will be challenged by further
   Finally, as for the polarity flip, consistently with the         studies in the future, which might even overturn our con-
masked-token experiments, the sentences containing the              clusions entirely, if a larger data set were considered. Fur-
morphological antonym were turned into positive using               thermore, it would be interesting to investigate whether
the lexical base fewer times than their lexical counter-            the results obtained for Italian are also found for other
parts, suggesting that the latter may have a more re-               languages that present both lexical and morphological
stricted semantic spectrum, contrary to our initial hy-             antonyms, including languages with a different morpho-
pothesis.7                                                          logical system. With a view of deepening the analysis
                                                                    methodologically, it would be interesting to focus on
                                                                    additional linguistic factors that might drive the choice
7. Conclusion and Future Work                                       between lexical and morphological antonyms, such as
                                                                    semantic networks or word frequency, and to expand the
Our study investigated the differences and competition
                                                                    testing to the psycholinguistic dimension.
between two types of antonyms, morphological and lexi-
                                                                       What is sure is that the relationship between mor-
cal, focusing on a computational account of their context
                                                                    phological and lexical antonyms is more complex than
of use. While a lexical analysis did not prove decisive,
                                                                    previously thought and that the choice of one type of
experiments on masked-token prediction and polarity
                                                                    antonym over another depends on a variety of intercon-
flip, aimed at approximating their semantic coverage, in-
                                                                    nected factors that are still to be fully unveiled.
dicate that, unlike what is suggested in some studies on
antonymy, the lexical antonym seems to have a narrower
lexical coverage and scope, supporting the view that it References
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APPENDIX A
                                                               accuracy     accuracy     accuracy     accuracy
        Noun                 infelice            triste
                                                                mtp (M)      mtp (L)      pf (M)        pf (L)
        matrimonio              886                24             0.9          0.5          0.2          0.4
        scelta                  821                39             0.8          0.5           0           0.1
        adolescenza             33                 16              1           0.2           0           0.2
        donna                   325               316             0.5          0.8          0.2          0.1
        uomo                    300               440             0.5          0.6          0.4          0.1
        situazione              120               339             0.4          0.9           0            0
        momento                 145              2.686            0.1           1            0           0.2
        pagina                  19                544              0            1           0.2           0
                                                               accuracy     accuracy     accuracy     accuracy
        Noun                impreciso      approssimativo
                                                                mtp (M)      mtp (L)      pf (M)        pf (L)
        affermazione            64                 11             0.2          0.8          0.1          0.1
        notizia                 223                58             0.4          0.8           0           0.1
        terminologia            23                 17             0.3          0.7          0.1          0.2
        ricezione               50                 18             0.7          0.3          0.2          0.1
        misurazione             31                 52             0.4          0.9          0.1          0.5
        traduzione              54                235             0.2          0.7           0            0
        conoscenza              33                226             0.1          0.9           0            0
        calcolo                 23               1.305            0.2           1           0.1          0.6
                                                               accuracy     accuracy     accuracy     accuracy
        Noun                 scorretto         sbagliato
                                                                mtp (M)      mtp (L)      pf (M)        pf (L)
        gioco                  1.124               72             0.1          0.7           0            0
        uso                    2.901              276              0            1            0           0.3
        alimentazione          2.926             1.228             0           0.9           0           0.1
        posizione              1.317              910             0.1           1           0.3          0.2
        abitudine               648              1.077            0.1           1           0.1           0
        informazione            720              1.903             0            1           0.2          0.3
        mossa                    90               741              0            1            0           0.1
        messaggio                88              1.214            0.1          0.9           0           0.1
                                                               accuracy     accuracy     accuracy     accuracy
        Noun               imprudente         avventato
                                                                mtp (M)      mtp (L)      pf (M)        pf (L)
        condotta                394               14              0.2          0.8           0           0.2
        comportamento           680               77              0.5          0.8           0            0
        parola                  49                46              0.3          0.5           0            0
        manovra                 24                35              0.5          0.6          0.1          0.4
        gesto                   54                195             0.7          0.4           0            0
        azione                  63                245             0.3          0.8           0            0
        scelta                  73                373             0.5          0.7           0            0
        decisione               24                478             0.5          0.5           0            0
                                                               accuracy     accuracy     accuracy     accuracy
        Noun               insufficiente        scarso
                                                                mtp (M)      mtp (L)      pf (M)        pf (L)
        apporto                 263               19              0.9          0.4           0           0.2
        quantità               1.097              162              1           0.4          0.1           0
        alimentazione           300               120              1           0.5           0            0
        produzione              208               158             0.9          0.4           0            0
        utilizzo                 16               27              0.9          0.9           0            0
        pulizia                  63               148             0.4          0.8           0            0
        partecipazione           13               37              0.5          0.9           0            0
        visibilità               14               274             0.4           1            0           0.1


Table 3
Co-occurrence frequencies of noun + morphological antonym and noun + lexical antonym.
Accuracy of the two task: mtp (Masked-Token Prediction) and pf (Polarity Flip) related to Morphological Antonyms (M) and
Lexical Antonyms (L).
                     morphological antonym             TTR          lexical antonym       TTR
                              infelice             0.4694864048            triste     0.4504979496
                            impreciso              0.4726656991      approssimativo   0.4814814815
                             scorretto             0.4496086106         sbagliato     0.4500775996
                           imprudente              0.476119403          avventato     0.4644572526
                          insufficiente            0.4582118562           scarso      0.4805725971


Table 4
Token Type Ratio of 5 antonym pair from sentences extracted from itTenTen20



APPENDIX B
system_message = '''In una frase l'aggettivo originale è stato sostituito da un token [MASK]. Tu devi riscrivere la
      frase facendo minimi cambiamenti e sostituire l'aggettivo mascherato con un altro aggettivo, in modo che la frase
       risulti volta al positivo.
Il tuo output deve essere SOLO un json nel seguente formato e con i seguenti campi:
    {"new_sentence": "",
    "new_adj": ""}'''
user_message = f'''Frase originale: "{masked_sent}" (aggettivo originale: {agg})'''


{system_message = f'''In a sentence, the original adjective has been replaced by a [MASK] token.
You need to rewrite the sentence making minimal changes and replace the masked adjective with another adjective, so
      that the sentence is positively oriented.
Your output must be ONLY a json in the following format and with the following fields:\n''' + '''{"new\_sentence": "<
      your new sentence>", "new\_adj": "