不定式作名词修饰语分为前置和后置两种。一,前置。单个不定式一般不能作前置修饰语,但不定式分句在某些情况下可以前置。1.带 to 不定式的被动态可置于否定词或别的副词之后与它们一起作前置修饰语;主动态有时也可以与形容词或副词一起作前置修饰语。在美国英语中它们之间须用连字号,在美国英语中有不用的倾向:a not-to-be-ignored gesture,the much-to-be-longed-fro place,a dif-ficult-to-operate machine,a too-simple-to-be-true dress,the soon-to-be Infinitive noun modifiers are divided into pre-and post-position two. One, front. A single infinitive cannot generally be used as a premodifier, but an infinitive clause can be prepended in some cases. 1. With to infinitive dynamics can be placed on negative words or other adverbs followed by pre-modifiers with them; main dynamics can sometimes be pre-modifiers with adjectives or adverbs. There must be a hyphen between them in American English and a tendency to use them in American English: a not-to-be-ignored gesture, the much-to-be-longed-fro place, a dif-ficult-to- Operate machine,a too-simple-to-be-true dress,the soon-to-be