在不定式中，小品词to有时可以省略。主要在以下几种情形中：
① 在由make, let, see, feel, watch, have, hear, help, notice, observe, listen to, look at等动词引出的作宾语补语的情况时。
② 在介词but, except, besides 后(动词谓语必须是do，否则还需要小品词to)。如;
What do you like to do besides swim and play football?
Before breakfast we have no class but (except) to read English aloud.
When the enemy surrounded the house, they had no choice but to burn all the important documents.
③ 在had better, had best, had as good(宁可), would rather … than, would sooner … than, might as well, rather than后。如：
He had as good study English instead of German. 他宁可学英语也不愿意学德语。
They would rather try and fail than give it up. 他们宁愿试了失败也不愿意轻易放弃。
Let’s finish the work now rather than leave it off till tomorrow. 我们最好今晚把这活干完也别推到明天。
He resigned rather than take part in such a diahonest transaction. 他宁愿辞职也不愿干这桩肮脏的交易。
I would rather die standing than live kneeling. 我宁愿站着死不愿跪着生。
④ 在下列固定词组中。
We’ll have to make do with dry bread. 我们用干面包凑合吧。
He made believe he was innocent. 他假装无辜。
Don’t let slip such a good opportunity to learn. 不要丢失这样一个好机会。
He let go (of) the rope. 我松了绳子。
I hear say that there’ll be an earthquake soon. 我听说不久要有地震。
Don’t let there be any noise. 不要再制造噪音了。