情態(tài)動詞

must can may will shall dare have to

need could might would should ought to had better

一、共同點(diǎn)

1.+do 2.+not+do 3.一般疑問句，情態(tài)動詞+主+do

need to do sth(need 不一定是情態(tài)動詞)

need doing=need to be done

例:The desk need to be rapaired/rapairing(rapair)

二、用法:

1.含義:

(1)must---否定 needn't/don't have to(不必)

mustn't(禁止)

非要，偏要 If you must know,$20 an hour

(2)can

強(qiáng)調(diào)做某事的能力

客觀存在

(3)would

強(qiáng)調(diào)人的意愿(愿意)

物的屬性

(4)shall

一，三人稱疑問句，征求許可

二，三人稱陳述句，承諾/威脅/命令/警告

當(dāng)主語為法律法規(guī)law/rule強(qiáng)調(diào)內(nèi)容(肯定用shall，否定用mustn't)

2.表推測

3.have done

選should(根據(jù)基本含義)