疑问词+不定式”是英语中很有用的结构。疑问词是疑问代词“who, whom, what, which, whose”和疑问副词“when, where, how”。

　　“疑问词+不定式”的结构主要有下列几种功用：

　　⑴作主语。如：

　　● When to hold the meeting has not yet been decided.

　　● How to cope with the rising cost of living becomes a daily discussion topic.

　　⑵作宾语。如：

　　● We must know what to say at a meeting.

　　● Do you know what to do?

　　⑶作表语。如：

　　● The problem is where to find the financial aid.

　　● The question is how to get there.

　　⑷作同位语。如：

　　● Tom had no idea which book to read first.

　　⑸用于双重宾语。如：

　　● I can tell you where to get this book.

　　● I asked him how to learn English.

　　注意：

　　1、并非所有动词都适用于“疑问词+不定式”结构，主要有：“know, see, decide, tell, ask, consider, discover, explain, forget, learn, remember, wonder, understand”等。

　　2、当这个结构作宾语时，它的作用相当于名词性从句。如：

　　● I could not decide which dictionary to buy. / I could not decide which dictionary I should buy.

　　● Jack did not know where to find such a good teacher./ Jack did not know where he could find such a good teacher.

　　3、有些动词，如“ask, show, tell, advise, inform, teach”等，可以先有个宾语，然后再接适当的“疑问词+不定式” 结构。如：

　　● The chief technician showed the apprentice how to repair the machine.

　　● Have you told him where to get the application form?

　　(文/宋焘； 英语辅导报高一普及版 04~05学年度第21期；版权归英语辅导报社所有，独家网络合作伙伴新浪教育，未经许可，不得以任何形式进行转载。)