不定式紧跟在这些动词之后作宾语
例如：
want to do sth 想要做某事,to do做want的宾语
Do you want to do sth tonight?
你今晚要做什么吗?
forget to do sth忘记做某事
I forget to do homework this morning.
我忘记今天早上做作业了.