非谓语动词是英语中除谓语动词外的其他语法功能动词，主要包括以下三种形式： 动词不定式（to do）、 动名词（doing）和 过去分词（done）。以下是具体说明及例句：
一、动词不定式（to do）
作主语 - It is important to protect the environment.
- The best way to learn a language is immersion.
作宾语
- I hope to travel around the world.
- The teacher asked us to finish the homework.
作定语
- The man to call you is my friend.
- The problem to solve is complex.
作状语
- To be honest, I don't like the movie.
- Having finished my homework, I went out to play.
二、动名词（doing）
作主语
- Swimming is my favorite sport.
- Reading books improves memory.
作宾语
- I enjoy painting in my free time.
- The company specializes in software development.
作定语
- The crying baby woke up the whole neighborhood.
- A busy day is always exciting.
作状语
- Listening to music helps me relax.
- The company is expanding rapidly.
三、过去分词（done）
作定语
- The broken window needs repair.
- A finished project is always a success.
作后置定语
- The man with the hat is my neighbor.
- The book written by him is very popular.
作状语
- The letter received yesterday was from my friend.
- The problem solved quickly prevented a disaster.
补充说明
动词不定式： 可表示具体或将来动作，常与 it
动名词：多用于表示习惯性或抽象动作，如 enjoying、 practising等。
过去分词：用于表示被动或完成状态，如 been finished、 having been written等。
通过以上分类及例句，可更清晰地理解非谓语动词的用法。
