为什么是you must finish doing your homework,而不是you must finish your homework?
问题描述:
为什么是you must finish doing your homework,而不是you must finish your homework?
答
finish doing sth 完成某事那finished my homework呢?这里must是情态动词,后面只能加动词原形,所以不可以用finished.那如果you must finish your homework,这样说是错的吗?也可以,finish (doing) sth,doing可以省略