第1个回答 2012-02-03
1. ought to在美国英语中,疑问、否定及简略答语中to可以省略:Ought I to go?Yes,you ought (to).
You ought not (to) do that sort of thing.
Oughtn't we send for the police?
2.used to在简略句中也可以省略to:
I don't swim so often as I used (to).
Used he to go to the market every Sunday? No, he usedn't (to).
3.动词不定式符合to的省略:
A)当几个不定式并列时,除了第一个不定式外,其余的不定式常省略to:
I wished to finish my business and get away.
Do you want to have supper now or wait till later?
B)当want,like用于从句时(如when、if、what、as从句),为了避免重复用to代替上文的动作但也常常连同不定式符合to一起省略:
You may do the experiment with them if you want (to).
C)如果不定式是be或have,则通常要保留:
China is no longer what it used to be.
He hasn't finished yet. Well, he ought to have.
Aren't you the manager? No, and I don't want to be.