1、12n一、疑問代詞who, what, which等和疑問副詞when, where, how等后面跟不定式，構成不定式短語。這種結構在句中可作主語、賓語、表語、賓語補足語等句子成分。3 作主語n1. 作主語：作主語時，謂語動詞常用單數形式。例如：nWhere to go tomorrow has not been decided. n明天到什么地方去尚未決定。n How to divide labor among the workers is still a question. n這些工人之間如何分工仍是個問題。4n2. 作賓語：能夠接疑問詞不定式作賓語的動詞常用的有advise, ask,

2、 consider, decide, discuss, explain, forget, know, learn, remember, show, teach, tell, wonder等。例如：nHe has to learn how to collect water, hunt for food, and make fire. n他得學會收集淡水、尋找食物，生火什么的。謂語部分作賓語5n 3. 作雙重賓語（賓語補足語）：某些動詞后面可接sb.疑問詞不定式構成的雙重賓語，這類動詞常用的有advise, ask, show, teach, tell等。例如：n He will advise y

3、ou what to do. n他會建議你們做什么。謂語部分賓語賓語補足語6n 4. 作介詞賓語：某些介詞后面可接疑問詞不定式作賓語，這類介詞常用的有 about, as, from, in, of, on, with等。例如：nHe has no idea of how to answer this question. n(no idea of this question)n他不知道怎樣回答這個問題。nYou have a number of topics from which to choose. n(choose from)n你有很多題目可以選擇。(which是關系代詞)介詞介詞賓語7n

4、5. 作表語 n 表語是說明主語身份,職業,性質,狀態或特征的句子成分，補充說明主語的意義，因此，它也叫作主語補語。表語一般用在連系動詞后面，連系動詞除了be之外，還有become（成為）、look（看起來）、turn（變成）、go（變成）、seem（似乎）、appear（似乎、顯得）、feel（摸起來）、sound（聽起來）、smell（聞起來）等等。可做表語的有: 形容詞、代詞、名詞、分詞、數詞、介詞短語或副詞和從句：例如： nWe are students. He is very clever. Her face turns red. 85、作表語nPerhaps the most di

5、fficult challenge is how to survive without friends. n也許最難熬的挑戰，就是生活中孤獨無友。 nThe question is which to choose. n問題是挑選哪一個。系動詞作表語9n二、“特殊疑問詞動詞不定式”這種結構可以把復合句轉為簡單句。如：nI dont know what Ill do next. n I dont know what to do next.nThe doctor told him when he should take the medicine. n The doctor told him when to take the medicine.n Li Ping doesnt know why to learn English. n Li Ping doesnt know why he should learn English.10nWhich to choose is important. n Which we should choose is important.nThe question is where to go.n The question is where we should go.