那个 可不可以举点例子啊？
追答My goal is to go to a famous university. (不定式to的短语放在be动词后面作表语)
I want to go to a famous university.(不定式to go...作宾语)
I came to see you. （不定式作目的状语）
Seeing is believing. (动词的ing形式分别作主语和表语)
I like swimming. (动词的ing形式作宾语)
The boy singing a song is my brother.(动词的ing形式作定语，表示主动)
The song written by my brother is very good. (过去分词作定语，表示被动)
呵呵，讲不完的。建议去书店买一本专门对非谓语动词有训练的参考书吧！有中学的语法讲解与专练也行。
祝你学习进步！