导读：英语中to既可以是不定式符号，后接动词原形;to也可以是介词，后接名词或动词的-ing形式。英语中有很多常用短语带有to，我们要正确判断to是不定式符号还是介词，千万不可混淆。下面和长沙新东方的小编一起来复习一下。

　　不带to的不定式

　　1.在口语中，动词原形come和go后可接不带to的不定式。

　　Go tell her.去告诉她吧。

　　Come have a glass.来喝一杯。

　　2.在why引起的一些问句中，疑问词直接跟动词原形或not+动词原形。

　　Why make so much noise 为什么发出这么大的噪音?

　　Why not join us 为什么不加入我们?

　　3.在had better, had best, would rather, would rather...than, would sooner, would sooner...than, cannot but, cannot choose but, cannot help but等结构后直接跟动词原形或not +动词原形。

　　You'd better listen to your teacher's opinion. 你最好听一听老师的意见。

　　We had best call for the doctor at once.我们最好马上就请医生来。

　　She can't do anything but ask silly questions.她一直在问一些愚蠢的问题。

　　Rather than ride on a crowded bus, he always prefers to ride a bicycle.他宁愿骑自行车，也不愿挤公共汽车。

　　He cannot but move to another street, because his building has to be pulled down soon.他不得不搬到另一条街上去，因为他住的大楼很快就要被推倒。

　　We cannot help but admire his courage. 我们情不自禁地钦佩他的勇气。

　　4.如不定式前有行为动词do，那么在表语从句中的不定式和介词except或but之后的不定式可不带to。

　　The only thing I could do was go home.我能做的唯一一件事就是回家。

　　They could do nothing but wait for the doctor to come.他们只能等待医生的到来。

　　5.在两个动词不定式并列使用时，为了避免重复，后面的不定式符号to可省略。

　　The little girl hardly knew whether to laugh or cry.这小姑娘不知道是哭好还是笑好。

　　Can you help me to call him and ask him to attend the meeting at 200 p.m.你能不能帮我打电话给他，叫他下午两点来开会?

　　6.在help之后，既可用带to的不定式也可用不带to的不定式。

　　Can I help (to) carry the box for you我帮你搬箱子，好吗?

　　7.在一些固定搭配中用不带to的不定式。

　　He let go the rope.他松开了绳子。

　　I hear say there will be an earthquake soon.我听说不久就要有一次地震。

　　She made believe she was innocent.她假装清白。

　　8.在感官动词see, hear, watch, feel, notice以及使役动词make, let, have等后作宾语补足语的动词不定式不带to。

　　She watched the children cross the street.她看着孩子们穿过了马路。

　　They made the boy apologize to his friend for being so rude.他们让那男孩因他的粗鲁而向他的朋友道歉。

　　Don't forget to have him come earlier.别忘了让他早点儿来。

　　(来源：新东方在线高考辅导)