济南考博培训

考博英语语法详解　　

考博英语语法：非谓语动词常考的其它结构
　　(1)疑问词 不定式结构
　　疑问词who，what，which，when，where和how后加不定式可构成一种特殊的不定式短语。它在句中可以用作主语、宾语、表语和双重宾语。如：
　　When to start has not been decided.何时动身尚未决定。(主语)
　　I don’t know what to do.我不知道该怎么办。(宾语)
　　The difficulty was how to cross the river.困难在于如何过河。(表语)
　　I can tell you where to get this book.我可以告诉你哪里可以买到此书。(双重宾语)
　　(注)A.有时疑问词前可用介词，如：
　　I have no idea of how to do it.我不知道如何做此事。
　　B.动词know 后面不能直接跟不定式作宾语，只能跟疑问词(如：how, what) 不定式：
　　While still a young boy, Tom knew to play the piano well and as he grew older, he wrote operas, the most famous of which is Carmen.