1、to后面接动词原形，构成动词不定式，to后面还可以接动名词，这时to作介系词来使用。
2、动词不定式是动词的一种非限定形式，由to加动词原形构成，在句中起名词、形容词和副词的作用，同时也保留动词的一些特征，可以带宾语、状语和宾语补足语等。
【拓展资料】：
to的用法
1、Two friends and I drove to Florida during college spring break
我和两个朋友在大学春假期间开车去了佛罗里达。
2、We went to a party at the leisure centre
我们去休闲中心参加一个聚会。
3、There was a piece of cloth tied to the dog's collar
狗项圈上系着一条布。
4、Hemingway's studio is to the right
海明威的工作室在右面。
5、He picked up the knife and gave it to me
他捡起刀子递给我。
6、Marcus has been most unkind to me today
马库斯今天对我非常无礼。
7、He is a witty man, and an inspiration to all of us
他机智风趣，鼓舞激励着我们所有人。
8、I'm going to have to explain to them that I can't pay them.
我将不得不向他们解释我不能付钱给他们。
9、To his surprise, the bedroom door was locked
令他吃惊的是，卧室门锁上了。
10、It was clear to me that he respected his boss
在我看来他显然很尊重他的上司。
11、The shouts changed to screams of terror.
喊叫声变成了惊恐的尖叫声。
12、Rickman worked as a dresser to Nigel Hawthorne
里克曼曾是奈杰尔·霍索恩的服装师。
13、Every vehicle was banned from coming into Mexico City one day a week from Monday to Friday
每周一到周五期间都会有一天禁止所有车辆进入墨西哥城。
动词+ing形式 指过去的事情或正在发生的事情。比如 stop doing sth(停止正在做的事情), forget doing sth.(忘记了做某事)
动词+ to + 动词原形 指即将发生的事情。 比如stop to do sth. (停下来去做某事)
绝大多数情况下，to后面接动词原形，但在几个特殊情况下，to后面加的是-ing形式
1. admit to / confess to doing something
承认/坦白做某事
e.g.admit to having stolen the car
承认偷车
2. oppose to / object to doing something
反对做某事
e.g.object to building the new airport
反对修建新机场
3. be devoted to / be dedicated to / be committed to doing something
致力于做某事
e.g.be dedicated to helping the poor
致力于帮助穷人
4. be used to / be accustomed to / adjust to doing something
习惯做某事
e.g.not used to eating much at lunch
不习惯中午吃很多
5. look forward to doing something
期待某事
e.g.I am looking forward to seeing you
很期待见到你
·以上这些的共同特点，是to后面都可以接名词，比如：
objective to his proposal
反对他的提案
所以-ing形式在这里起到了动名词的作用，用法与名词是一致的。
参考资料：新东方英语