英語四級(jí)語法備戰(zhàn)-情態(tài)動(dòng)詞用法辨析大總結(jié)

       七、should 和ought to

　　should 和ought to 都為"應(yīng)該"的意思，可用于各種人稱。

　　——Ought he to go?

　　——Yes. I think he ought to

　　表示要求，命令時(shí)，語氣由 should（應(yīng)該）、had better最好）、must（必須）漸強(qiáng)。

　　八、 had better表示"最好"

　　had better 相當(dāng)于一個(gè)助動(dòng)詞，它只有一種形式，它后面要跟動(dòng)詞原形。

　　had better do sth

　　had better not do sth

　　It is pretty cold. You'd better put on my coat

　　She'd better not play with the dog.

　　had better have done sth表示與事實(shí)相反的結(jié)果，意為"本來最好"。

　　You had better have come earlier.

　　九、 would rather表示"寧愿"

　　would rather do

　　would rather not do

　　would rather… than…　寧愿……而不愿。

　　還有would sooner, had rather, had sooner都表示"寧愿"、"寧可"的意思。

　　If I have a choice, I had sooner not continue my studies at this school.

　　I would rather stay here than go home. = I would stay here rather than go home.