Semantic analysis of verbal collocations with lexical functions

Lexical function is a concept that formalizes semantic and syntactic relations between lexical units. Relations between words are a vital part of any natural language system. Meaning of an individual word largely depends on various relations connecting it to other words in context. Collocational relation is a type of institutionalized lexical relations which holds between the base and its partner in a collocation (examples of collocations: give a lecture, make a decision, lend support where the bases are lecture, decision, support and the partners, termed collocates, are give, make, lend). Collocations are opposed to free word combination where both words are used in their typical meaning (for example, give a book, make a dress, lend money). Knowledge of collocation is important for natural language processing because collocation comprises the restrictions on how words can be used together. There are many methods to extract collocations automatically but their result is a plain list of collocations. Such lists are more valuable if collocations are tagged with semantic and grammatical information. The formalism of lexical functions is a means of representing such information. If collocations are annotated with lexical functions in a computer readable dictionary, it will allow their precise semantic analysis in texts and their effective use in natural language applications including parsers, high quality machine translation, periphrasis system and computer-aided learning of lexica. In order to achieve these objectives, we need to extract collocations from corpora and annotate them with lexical functions automatically. To this end, we use sets of hypernyms to represent the lexical meaning of verbal collocations and evaluate many supervised machine learning techniques on predicting lexical functions of unseen collocations. to train algorithms, we created a dictionary of lexical functions containing more than 900 disambiguated and annotated examples. The dictionary is a part of this book. The obtained results show that machine learning is feasible to achieve the task of automatic detection of lexical functions.