1)情態(tài)動詞can(能夠)，must(必須)，may(可以)

　　結(jié)構(gòu)：主語+can/must/may+動詞原型

　　He can make the tea.

　　Sally can air the room.

　　We can speak English.

　　★變疑問句將情態(tài)動詞移到句首

　　Can he make the tea?

　　Can Sally air the room?

　　Can we speak English?

　　★變否定句在情態(tài)動詞后面加not

　　He cannot make the tea.

　　Sally cannot air the room.

　　We cannot speak English.

　　★肯定回答及否定回答

　　Yes, he can. / No, he cannot.

　　Yes, she can. /?No, she cannot.

　　Yes, we can. / No, we cannot.

　　★特殊疑問句：(必背)

　　What can you do?

　　注意：情態(tài)動詞的句子沒有第三人稱單數(shù)的變化，不要在情態(tài)動詞或動詞后面加s。

　　2)must/have to的區(qū)別

　　must 表示必須，是主觀上覺得應(yīng)該做，have to是不得不，是由于客觀條件逼迫的必要要做

　　must 只能用在表示現(xiàn)在和將來的句子里，而have to do可以用在任何時態(tài)

　　3)must, may, might表示猜測：

　　· must do 表示對現(xiàn)在事實(shí)的猜測

　　· must have done表示對過去事實(shí)的猜測

　　· must have been doing 表示對過去正在進(jìn)行的事實(shí)的猜測

　　· may/might do, may/might have done表示沒有任何事實(shí)依據(jù)的猜測，might的可能性更小。

　　4)can't/couldn't 表示不可能

　　情態(tài)動詞

　　~~~【每日一練】~~~

　　1. _____ you ready? (A) Are (B) Have (C) Will (D) Can

　　2. ____ here early? (A) Will he (B) Was he (C) Did he be (D) Were he

　　3. I ___ happy about the price of eggs. (A) am't (B) am not (C) do not (D) won’t

　　4. Since last year I____ him only once.

　　(A) have seen (B) have been seeing (C) see (D) was seeing

　　5. Donald ___ sixteen tomorrow. (A) is being (B) going to be (C) shall be (D) will be

　　6.I ___ the story at all. (A) don't like (B) like(C)am fond of(D) would like

　　7.I would rather ___ than play now. (A) to study (B)am studying(C) study(D) studied

　　8.I'd rather you ___ anything about it for the time being.

　　(A) do (B) didn't do(C)don't (D) didn't

　　9.The car___much money.

　　(A) not cost (B) not have cost (C) isn't cost (D) didn't cost

　　10. I ___ like to eat fish. (A) am (B) have (C) do (D) be