Semantic annotation of Common Lexis Verbs of Contact in B ulgarian (2023)

Abstract: The paper presents the work on the selection, semantic annotation and classification of a group of verbs from WordNet, characterized with the semantic primitive ‘verbs of contact’ that belong to the common Bulgarian lexis. The selection of the verb set using both different criteria: statistical information from corpora, WordNet Base concepts and AoA as a criterion, is described. The focus of the work is on the process of the verbs’ of contact semantic annotation using the combined information from two language resources - WordNet and FrameNet. The verbs of contact from WordNet are assigmed semantic frames from FrameNet and then grouped in semantic subclasses using both their place in the WordNet hierarchy, the semantic restrictions on their frame elements and the corresponding syntactic realization. At the end we offer some conclusions on the classification of ‘verbs of contact’ in semantic subtypes.

## introduction verb classes are sets of verbs sharing similar semantic properties, such as the membership to a common semantic domain or similar argument realization and semantic interpretation. @xcite emphasizes the importance of verb classes in various tasks including the study of the patterns of shared verb behavior; the organization of the verb lexicon; the identification of grammatically relevant elements of meaning. wordnet and framenet are large lexical resources that provide semantic information about verb classes. wordnet (wn) @xcite represents a multilingual conceptual network of synonym sets (synsets) linked by means of semantic relations such as hypernymy, antonymy, etc. framenet (fn) @xcite represents the semantics of lexemes by means of schematic representations (frames) describing objects, situations, or events and their components (frame elements) in the apparatus of frame semantics. the aim of this paper is to present an ongoing work on the semantic annotation and classification of a subset of bulgarian 'verbs of contact' that belong to the general lexis of bulgarian. the goal of these efforts is to contribute both to the enrichment of the bulgarian wordnet with conceptual frames @xcite and to the enlargement of the bulgarian framenet, and hence -to the creation of a linked semantic and syntactic resource. ## the data analyzed the analyzed verbs and the corresponding semantic descriptions were extracted from the interrelated language resources: wordnet @xcite and framenet @xcite . the combined information available in the resources results in a rich representation of the paradigmatic and syntagmatic aspects of lexical semantics @xcite . the implementation of the mapping of fn frames to wn synsets is described in detail in @xcite . the selected set of verbs (i.e. the wn verbs of contact) was subsequently filtered so as to include only verbs belonging to the general lexis of bulgarian. ## related work verbs of contact are heterogeneous and overlapping as a semantic class and thus less studied than other verb classes. they have been an object of research for english @xcite ; @xcite and chinese @xcite . @xcite focuses on two large classes of verbs of contact, break and hit, whose members share elements of meaning and patterns of behavior. a class of contact verbs was also defined by @xcite in her semantic classification on the basis of a number of alternations reflecting the correlation between the semantics and the syntactic behavior of the verbs and the interpretation of their arguments. in particular, @xcite : (148-156) defines a class of verbs of contact by impact with a number of subclasses: hit verbs; spank verbs; swat verbs; non-agentive verbs. dimitrova-vulchanova and dekova (2009) represent a corpus and an empirically-derived classification of verbs of contact by impact using the sign model formalism. individual subtypes of the class were also described by some authors: physical contact verb @xcite and hit and spank verbs of contact by impact from @xcite . these descriptions and classifications partially overlap with the classification adopted in wordnet; their correspondences in framenet are less hierarchically structured. previous work on the conceptual semantic annotation of bulgarian verbs involves the analysis of verbs of change @xcite and verbs of communication @xcite . different stages of the study of semantic features and selectional restrictions relevant to the semantic description of bulgarian verbs and their frame elements are explored in @xcite . verbs of contact have not been described for bulgarian so far. ## semantic features of verbs of contact in this section i use the semantic characterization of verbs of contact and their division into subclasses proposed by @xcite with a view to the wordnet hierarchy, in combination with additional semantic information from framenet. lexical semantic subtypes being the largest class of verbs in wordnet, the set of contact verbs is well-represented in the selection of bulgarian general lexis verbs -nearly 7% of the whole set. most of the contact verbs are hypernyms of the following central verb concepts: fasten, attach, cover, cut and touch, which results in a large tree structure within the set @xcite . based on the wordnet hypernym relation, the following subgroups of contact verbs have been defined: (a) verbs encoding force, intensity, or iteration of the action (hit). (b) verbs of holding (grab, squeeze, pinch) and touching (paw, finger, stroke, poke). (c) verbs involving an instrument or material argument (paint). (d) verbs involving a body part argument indicating what kind of contact action the body part is typically used for: shoulder (support, carry); elbow (push); finger, thumb (touch, manipulate). ## annotation of verbs of contact and semantic frames assignment the annotation of bulgarian contact verbs with semantic frames and the description of their semantic features -i.e. their frame elements 3 and the relevant semantic restrictions is part of the description of conceptual frames in bulgarian. conceptual frames are abstract structures, that describe a particular types of situations or events, along with its participants and properties @xcite . the annotation is carried out by means of a software system called bulframe specifically designed for the definition and description of conceptual frames @xcite the semantic restrictions imposed on the verb's arguments were aligned 3 elements which correspond to core fes in framenet are semantically essential components of a frame that can be recovered from the context with (a) particular subtree(s) of noun synsets in wordnet and draw on previous efforts described in @xcite . the annotation of the selected verbs includes the following steps: (a) each verb is assigned a framenet frame (as is), a framenet frame that has been modified to better reflect the semantics of the verbs under discussion or a newly formulated frame. (b) the restrictions which are relevant for the entire frame are examined and revised if needed; these restrictions have been defined on the basis of the combined semantic information from wn and fn. (c) for each core frame element in a given frame a linguist checks the validity of the general selectional restrictions assigned to it. at this stage the linguist is able to verify the accuracy of the frameto-synset assignment and to make changes if necessary. the restrictions assigned to a frame give a first approximation of the semantic specification of the frame elements. when a general restriction is assigned, all hyponyms of the noun synsets, representing the roots of the relevant subtrees foot_2 , are potential candidates for the fe in context. (d) each verb is examined individually in order to specify additional selectional restrictions from wordnet if needed. specific restrictions on the lexical realization of the fes are represented as individual wn synsets. ## annotation of verbs of contact -semantic classes, semantic frames and restrictions in this section i provide an analysis of the verbs of contact which have been assigned one of a number of selected frames denoting contact and a description of their selectional restrictions. the semantic restrictions describing the compatibility between semantic classes of verbs and nouns corresponding to their arguments proposed in @xcite are aligned with the noun synsets representing the roots of the subtrees. the grouping of verbs of contact into subtypes is based on the hypothesis that verbs with similar meanings have characteristic argument realization patterns shared by their members. it is necessary to take into account the semantics of a verb's arguments in order to determine whether a particular verb construction is acceptable. 31 frames were assigned to verbs of contact included in the selection of bulgarian general lexis verbs so far. the contact predicates are divided into 2 subgroups that combine semantic components of contact via motion and state verbs for physical contact. the most typical arguments in their semantic frames are theme, force, body part, source, frequency, and instrument. some of the frames are analyzed and commented below with a view to the assignment of more refined selectional restrictions. ## syntactic patterns the observations on the syntactic behavior of the studied verbs led to the delineation of several general syntactic constructions within the group: (a) np(pro-drop subject) verb np(direct object -theme) pp(non-obligatory indirect object -to/on/over destination) this syntactic structure is typical for verbs selecting a theme as an object, for instance razleya (pour) -razlya chaya po masata. ('she poured the tea over the table '). (b)np(pro-drop subject) verb np(direct object -destination) pp(non-obligatory indirect objectwith theme). this pattern is found with verbs taking the fe destination as an object, for instance namazha (spread) -namaza filiyata s maslo. ('she spread butter on the slice'). (c) np(pro-drop subject) verb np(direct object -location/container) pp(non-obligatory indirect object -with theme). this type of structure is typical for verbs selecting the fe location/container as an object as in natovarya (load) -natovariha kamiona s kutiite ('they loaded the truck with the boxes'). ## results and discussion the annotation results presented in the paper are preliminary as they are part of a work in progress. a total of 381 contact verbs were assigned 26 fn frames, most of which have been manually checked and assigned general selectional restrictions. the description of the syntactic properties and the definition of more specific selectional restrictions for each verb are still in process, covering mainly the root synsets (section 6). the contact verbs were grouped in two main subcategories -verbs of physical contact via motion and state verbs of physical contact with different subgroups according to the features manner and point of the contact. the process of annotation raises some interesting questions regarding the language-specific lexicalization patterns of some bulgarian verbs as compared with their english counterparts. the syntactic expression of some of the fes differs in the two languages. the obligatoriness of the syntactic realization depends on the point of contact between the core frame elements. the english verbs of contact that encode one of the frame elements in their morphological structure -e.g. the instrument (knife), the resultant shape (slice), the covering material (paint), the container (box, bag), etc. -have different lexicalization in bulgarian. not all the bulgarian correspondences have the frame element incorporated in their word structure. for example the english verb cream: 3 (eng-30-01364483-v 'put on cream, as on one's face or body') -has no one-word correspondence in bulgarian and is translated as the expression namazvam s krem: 1, where krem is the theme, compare: she creamed her face (destination) and namaza s krem (theme) liceto si (destination). on the other hand some of the bulgaraian verb hyponyms express a specific manner by means of prefixation, e.g. razryzvam: 2 (cut: 35 eng-30-01552519-v 'cut into pieces'). such predicates lexicalize a meaning component which specifies a scale of motion or state and contact and do not have full one-word correspondences in english. these and other similar cases have necessitated the modification of fn frames or the definition of further specifications. the above observations led to the hypothesis that different word formation mechanisms across the languages, such as derivation, compounding and conversion as well as lexical gaps, reflect differences in the semantic structure of lexemes. ## conclusions and future work the research described in this paper is part of an effort towards the enrichment of the set of bulgarian general lexis verbs derived from the bulgarian wordnet with frame semantics from framenet and the definition of multifunctional relations between the verbs and the noun classes representing the selectional restrictions imposed on their participants. i also advance a number of observations on the interaction between syntax and semantics with reference to the behavior of bulgarian verbs of contact, their arguments and their ontological place in the hierarchy of the bulnet structure. as the proposed analysis is based on multilingual resources such as wordnet and framenet some of the observations may also be useful for other languages and may contribute to the implementation of nlp applications aimed at automatic semantic analysis, word sense disambiguation, language understanding and generation, machine translation, etc.