動詞不定式

用作介詞的to

to 有兩種用法：一為不定式+動詞原形; 一為介詞+名詞/動名詞, to 在下面的用法中是第二種，即to+ 名詞/動名詞：admit to承認(rèn)，confess to承認(rèn)，be accustomed to 習(xí)慣于，be used to 習(xí)慣于，stick to 堅持，turn to開始，著手于，devote oneself to 獻(xiàn)身于，be devoted to 致力于， look forward to 盼望，pay attention to

注意

省to 的動詞不定式

1) 情態(tài)動詞 ( 除ought 外，ought to)：

2) 使役動詞 let, have, make：

3) 感官動詞 see, watch, look at, notice , observe, hear, listen to, smell, feel, find 等后作賓補(bǔ)，省略to。

注意

在被動語態(tài)中則to 不能省掉。

I saw him dance. =He was seen to dance.

The boss made them work the whole night.=They were made to work the whole night.

4) would rather，had better：

5) Why… / why not…：

6) help 可帶to，也可不帶to, help sb (to) do sth：

7) but和except：but前是動詞do時，后面出現(xiàn)的動詞用不帶to的動詞不定式。

8) 由and, or和than連接的兩個不定式，第二個to 可以省去：

9) 通常在discover, imagine, suppose, think, understand等詞后，可以省去to be：He is supposed (to be) nice.　他應(yīng)該是個好人。舉例：He wants to move to France and marry the girl. He wants to do nothing but go out. 比較：He wants to do nothing but go out. He wants to believe anything but to take the medicine.