1、精選優(yōu)質(zhì)文檔-傾情為你奉上情態(tài)動詞一 情態(tài)動詞類型：1） 只作情態(tài)動詞：must, can(could), may(might), ought to2） 可作情態(tài)動詞也可作實義動詞：need, dare3） 可作情態(tài)動詞，也可作助動詞：shall(should), will(would)2 情態(tài)動詞分別講解1.Must1)“必須，一定要” 可用于肯定句，表示說話人的主觀意志，否定句表示禁止聽話人干某事，疑問句中表示征求聽話人意見，是否必要做某事。 We must be confident in ourselves. You mustnt smoke in the classroom. -Mus

2、t we hand in our exercise in class? -Yes, you must. / No, you neednt/ dont have to.2)表推測，“必然，必定”只用于肯定句，不用于疑問否定句中。 (1) 現(xiàn)在的肯定推測：must do He must be mad. (2) 現(xiàn)在正在進(jìn)行的動作：must be doing They must be waiting for us. (3）過去的肯定推測：must have done The door is locked. They must have left.3)“偏要，硬要”表示不耐煩。 Must you sm

3、oke here?2.Can 1)“能，會”強調(diào)人和動物所具有的能力。 Ducks can swim. I can speak English. 2)“可以，許可”You can smoke here. 3)表示事物發(fā)生的可能性，表“推測”。肯定句：理論上、客觀上的可能性。Jiangsu can be warm in July.疑問句或否定：具體事實的可能性。表示疑惑，驚訝或者不相信的意思。How can he be rude to you?3.Could 1)can的過去式：“可能，許可”He told me that he could lift more than 100 kilogram

4、s. The teacher tome me that I could hand in my homework later. 2)could提要求，比can更委婉。 -Could I ? Yes, you can. Can you? -Yes, I can. 3)對過去情況的推測：could （not）have done : (1)對當(dāng)時情況推測：（當(dāng)時可能/ 不可能）You could have hurt someone.(有可能做了，也有可能沒做) (2)虛擬（對過去）（本來可以/ 不可以）I could have gone to help you. Why didnt you ask m

5、e?(本來可以卻沒做)4.May 1)許可，允許： You may join us in the game. 注意否定回答：-May I smoke here? -No, you cant/ mustnt./ -No, youd better not/ Im afraid not. 2)可能。不用于疑問句。Youd better take a map with you, or you may lose your way. 注意：May he is innocent of the robbery?(錯，換成can/ could) 3)may have done: 推測，不用于疑問句。也沒有虛擬意

6、味。 Our teacher may have mistaken my mother for my sister.(可能性)5.Could 1)作may 的過去式。表過去的“許可，允許”用于間接引語。 He asked “Can/ May I sit down?” He asked if he could sit down. 2)對現(xiàn)在情況推測，可能性比may 小。He might be here on time, but I am not sure. 3)用于疑問，客氣委婉的提出請求。 -Might I come in? -Yes, you may. 4)might have done= c

7、ould have done對過去事情的推測，可能做了。還可用于虛擬 He might have got caught in the shower. You might have persuaded him into giving up the idea, but you didnt try your best.(虛擬)6.Should/ Ought to 1)應(yīng)該，應(yīng)當(dāng)（義務(wù)） :You should stick to your opinion. 2)推測，用于陳述句。“按理應(yīng)當(dāng)，估計”：They should be there by now, for they have been away

8、 for two hours. 3)should (not) have done 本應(yīng)該/ 本不應(yīng)該 You shouldnt have scolded the boy for he has tried his best.(本不應(yīng)該卻做了) 4)竟然：從句中用來表示驚訝，不以為然: He should have fallen asleep in the class.7.Shall 1)主語的意愿決心。用于第一人稱：I shall follow you wherer you go. 2)表示建議/請求，用于一，三人稱疑問句：Shall we go for a walk? 3)表示說話人給予對方的

9、允諾，命令，警告，威脅，決心等。用于二，三人稱 You shall fail of you dont work harder.(警告) If you finish the work ahead of time, you shall have a week off.(許諾) Nobody shall stay in the class when class is over.(命令)8.will/would 1)表意愿（would表過去意愿）:I will make him change his mind even if I stay up all night. They asked us if

10、we would have a look-round first. 2)表請求，建議（用于第二人稱）（would 語氣更委婉） Will you drop in and have a chat with me ? Would you come to my office when it is convenient? 3)表示傾向，習(xí)慣（肯定句）總是，會 （否定句）不肯，就不 （would表過去的習(xí)慣） A drowning person will catch at a straw. The old couple would take a walk on fine afternoons.9.Need/ Dare 1)情態(tài)動詞：need /dare ( not) do sth. Need/Dare+主+do？實義動詞：need /dare to do sth. dont need/ dare to do sth. Do+主+need/ dare to do sth?Need you go so soon? Do you nee