有些动词后接不定式作宾补时，如果句意清楚，通常可以省略不定式中的动词原形，而只保留不定式符号to。这些动词常见的有advise, allow, ask, expect, forbid, force, order, permit, persuade, tell, warn, wish 等。如：

He often does things you wouldn’t expect him to. 他常做出谁也料不到的事。

Next time I hope you’ll go where I tell you to. 下次我希望你去我告诉你去的地方。

She wants to come but her parents won’t allow her to. 她想来，可是她父母不让。

I took this road because the policeman told me to. 我走这条路是因为警察叫我走的。

If he doesn’t want to do it, we’d better not force him to. 如果他不想这样做，我们最好别勉强他这样做。

若接不定式作宾补的动词为被动式，那么该不定式就不是宾补，而是主补（主语补足语）了。如：

I did it in the same way as I was told to. 人家叫我怎样干，我就怎样干。

He will never do such a thing though he should be forced to. 他即使被迫也绝不会做这样的事。