非谓语动词有三种:不定式、动名词、现在分词,这三种怎么区分,谢谢_百度...答:To be frank with you, he is good-for-nothing.5,疑问词+不定式=名词短语形式:where to go, what to do, how to swim, which to buy, when to do it等用法:这种不定式形式相当于名词短语,可以充当主语,宾语,表语。做主语 what to do was the question.作宾语 He is learning how to do it.做表语...