“何必”的词汇化形成于六朝,唐以后渐趋定型,发展到现在已经是较为成熟的语气副词。所跟成分的述谓性变化、语境信息的转变是其词汇化的诱因。“何必”的主观化,与“何必”句相关联系项的性质变化以及语用推理有很大关系。“何必”与“又”“呢”的关系,则与功能匹配、磨损补救和语境的适切性有关。 “Why ” lexicalization formed in the Six Dynasties, Tang gradually become stereotypes, the development has now become more mature modal adverbs. The content of the predicate changes, the change of context information is the inducement of its vocabulary. The subjectivity of “why” and the change of the nature of the related items of “why” and the pragmatic reasoning are closely related. The relationship between “why” and “” and “?” Is related to the matching of functions, wear-recovery and the relevance of context.