1、当to作为动词不定式的标志时，后面加动词原形，作为介词的词性时，用v-ing的形式。
2、to主要用于作不定式成分，动词分及物动词和不及物动词，to作不定式就是要修饰不及物动词后面的不定成分。
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。