semantic aspects of "bayad" (must) in persian

“ba:y?d” as a persian lexeme is interwoven with modality, a semantic category and therefore has a complicated and thought- provoking semantic nature. this paper uses evidence from persian to investigate the usage of this lexeme and some of its semantic and pragmatic aspects in this language. the results indicate that this lexical category can convey a wide range of modal meanings in different contexts. while “ba:y?d” is widely used to transfer agent- oriented modal meanings, it has a limited number of speaker- oriented or epistemic interpretations. it seems that this pattern of use can be explained through some diachronic considerations. using a pragmatic framework, one can study the diversity of the modal meanings of this category in a convincing way. such a framework provides supporting clues for considering of the indispensable role of context and also factors like tense and modal hedges in analyzing the semantic aspects of “ba:y?d”.