非谓语动词包括：不定式、动名词、分词(现在分词和过去分词)在这三种形式中，可作主语的有：不定式和动名词。

不定式作主语：

To say is one thing and to do is another.

To see is to believe.

动名词作主语：

Teaching you Chinese is my job.

Being a scientist is my dream.