This paper presents some hypotheses about the lexicon. As those hypotheses are included in a specific thematic role theory, I briefly outline some of the main points of this theory, which can be inserted in the field of lexical semantics (it is based on lexical items and their composition). I conclude with some arguments in favor of the inclusion of this model in a grammatical theory, using for that some empirical evidence from Brazilian Portuguese.
Lexical Semantics; Thematic Role Theory; Compositional Analysis; Grammatical Theory