不定式

　　1) 不定式常在下面動詞后面作賓語：afford, agree, arrange, ask, attempt, beg, care, choose, claim, decide, desire, determine, expect, fail, hope, pretend, promise, refuse, learn, tend, long, manage, offer, plan, prepare, etc.

　　2) 動詞 + it(形式賓語) + 形容詞(賓語補足語)+ 不定式(真正賓語)，適用于此結(jié)構(gòu)的動詞：believe, consider, feel, find, realize, see, suppose, think, understand etc.

　　We found it impossible to get everything ready in time.

　　3) “Wh- word + 不定式” 結(jié)構(gòu)

　　advise, decide, discuss, find out, know, learn, see, teach, tell, show understand, wonder 等

　　He does not know when to start.

　　You can decide whether to continue or to stop.

　　I will show you how to deal with it.

　　注意下面兩個句子的區(qū)別：

　　I cannot decide which restaurant to go to. / I cannot decide where to go.

　　不定式作賓語補足語

　　1) 動詞ask, advise, allow, beg, cause, command, direct, enable, encourage, expect, feel, force, have, hear, invite, lead, let, make, notice, order, permit, persuade, tell, urge, watch, see, require etc.

　　2) 下列詞組后面的不定式不帶to：would rather … than… (寧愿…也不)，had better ，can’t help but …(不得不), may/might as well … (不妨)

　　務(wù)必注意的是：接不帶to的不定式作賓補的動詞改成被動形式時必須加to。

　　He has seen nine presidents come and go.

　　Nine presidents have been seen to come and go (by him).

　　He will make you announce the news.

　　You’ll be made to announce the news.

　　不定式作狀語:表示行為的目的，結(jié)果

　　注意 so as to和in order to的區(qū)別

　　so as to 句中

　　(in order) to 句首或句中

　　下列結(jié)構(gòu)表示結(jié)果：

　　enough to …(注意enough的位置),

　　too … to…,

　　only to…

　　I rushed to the station as fast as I could, only to find the train already gone.

　　不定式的時態(tài)

　　1) 完成式:不定式的動作在謂語表示的動作之前完成,或想像中過去的動作或事情,但并沒有發(fā)生。

　　This book is said to have been translated into dozens of languages in the last decade.

　　The plane was to have taken off at six, but something went wrong.

　　2) 進行式：

　　The children appear to be enjoying themselves at the party.

　　注意不定式的邏輯主語 of sb./for sb.

　　It is quite important for us to learn a foreign language well.

　　It is very kind of you to tell me the truth.

　　判斷標準

　　(1) 看形容詞的性質(zhì) 當作表語的形容詞表示人的品質(zhì)特點時(如： careless, clever, considerate, foolish, good, impolite, kind, naughty, nice, silly, stupid, wise 等)作表語時，邏輯主語用of 引出

　　(2) 如果能改成 Sb. be +adj.+to do sth. 就用of.