“你要吃东西”如果用做祈使句,表示“必要”义;如果用做疑问句,表示“意愿”义。本文从这点出发,主要讨论并指出如下几点:(一)助动词“要”的多义多功能不是词汇平面的现象,而是由两个不同语义指向(主语指向和说话人指向)引起的语用现象;(二)助动词“要”有两个否定形式“不要”和“不想”的原因及其分工;(三)除“要”字外,现代汉语还有“怕”“不知道”等说话人指向的谓词性主观化成分;(四)从动词、助动词的“要”转为连词“要是”“只要”的语法化动机及其趋势。 “You want to eat ” If used as imperative sentence, said “necessary ” meaning; if used as interrogative sentence, said “meaning ” meaning. From this point, this paper mainly discusses and points out the following points: (1) The polysemy and multi-function of the auxiliary verb “want ” is not a phenomenon of the lexical plane but consists of two different semantic points (the subject points and the speaker points) (2) the auxiliary verbs “have ” have two negative forms “no ” and “do not want ” the reason and division of labor; (c) in addition to “to ”, the modern (4) From the verb, the auxiliary verb “To ” into conjunctions “If ” "As long as the Grammatical Motives and Trends.