省to 的动词不定式
1） 情态动词 ( 除ought 外，ought to)： 2） 使役动词 let, have, make： 3） 感官动词 see, watch, look at, notice , observe, hear, listen to, smell, feel, find 等后作宾补，省略to。 注意：在被动语态中则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 可带to，也可不带to, help sb (to) do sth： 7） but和except：but前是动词do时，后面出现的动词用不带to的动词不定式。 8） 由and, or和than连接的两个不定式，第二个to 可以省去： 9） 通常在discover, imagine, suppose, think, understand等词后，可以省去to be： He is supposed (to be) nice. 他应该是个好人。 10）but作介词，后接不定式结构时，前面谓语动词部分若含有do的形式时，but后的不定式要省去to，否则要带to。 He wants to do nothing but go out. He wants to believe anything but to take the medicine..下列动词或词组都可以用不定式(to do)： afford aim agree arrange ask decide bother care choose demand desire determine elect endeavor hope fail help learn long 渴望 mean manage offer plan pretend refuse tend undertake expect hate intend
