To be a teacher is my dream.

问题描述:

To be a teacher is my dream.
这句话中,是不是动词不定式作主语?如果是,那么这里的动词不定式应该是:to be还是to be a teacher?
我刚学英语

1.是动词不定式短语做主语的
2.动词不定式短语是to be a teacher