before后面的动词的形式
来源:学生作业帮 编辑:百度作业网作业帮 分类:英语作业 时间:2024/08/17 19:12:33
before后面的动词的形式
一定要加ing吗?如果想表示过去怎么办?
举个后面跟过去式的例子吧
一定要加ing吗?如果想表示过去怎么办?
举个后面跟过去式的例子吧
![before后面的动词的形式](/uploads/image/z/6892304-32-4.jpg?t=before%E5%90%8E%E9%9D%A2%E7%9A%84%E5%8A%A8%E8%AF%8D%E7%9A%84%E5%BD%A2%E5%BC%8F)
efore既是介词又可以作为引导时间状语的重句的连词,更可以做副词.
1作为介词,那么后面出现动词需要用动词ing形式,因为介词后面一般都是名词.比如:You mustn't hang out before finishing your assignment.
2before作为连词.Make sure that you lock the door before you leave the room.但有点需要注意,就是如果从句是过去式,那主句需要用过去完成式.I had been there for more than 15 years before I decided to depart for China.
3before作为副词.I have never met that man before.
1作为介词,那么后面出现动词需要用动词ing形式,因为介词后面一般都是名词.比如:You mustn't hang out before finishing your assignment.
2before作为连词.Make sure that you lock the door before you leave the room.但有点需要注意,就是如果从句是过去式,那主句需要用过去完成式.I had been there for more than 15 years before I decided to depart for China.
3before作为副词.I have never met that man before.