一般认为「,～タイ」只用于第一人称的意愿表达,但在实际使用中,却存在着数量不少的用于表达期待他人实现某事态的道义情态用法。本文通过对语例的分析,细致描写了「～タイ」的道义情态语义特征,对「～タイ」的道义情态特性进行了重新界定,并探讨了其语义转化机制,最后还梳理了其由意愿表达到道义情态的实现条件。 It is generally accepted that “イ イ イ” is used only for the first person’s wish expression, but in actual use, there are a large number of moral modus operandi expressions for expecting others to realize something. Through the analysis of the examples, this thesis elaborates on the semantic features of the moral modality of “~ イ イ”, redefines the moral modality of “タ イ” and discusses its mechanism of semantic transformation. Finally, To express the realization of moral conditions.