前面有to了后面的可以省略
动词不定式是由“to+动词原形”构成的。在实际运用中，小品词to在某些场合会被省略，下面简要归纳一下这些特殊情况。

1．在某些表示感官的动词（组）如fell, listen to, hear, look at, see, watch, notic等的复合宾语中，动词不定式不带to。例如：

We often hear her sing this song.

我们经常听到她唱这首歌。

I saw him play basketball.

我见过他打篮球。

2．在使役动词make, let, have等的复合宾语中，动词不定式不带to。例如：

Now let me hear you play.

现在让我听你演奏。

They made him work all day.

他们让他整天工作。

注意：上述两类句子若是变为被动语态，则原来作宾语补足语的不定式须带to。例如：

She is often heard to sing this song.

He was made to work all day.

3．动词help的复合宾语中，动词不定式既可带to，也可不带to。例如：

Will you help me learn English?=Will you help me to learn English?