before后加动词是吗形式?

题目

before后加动词是吗形式?

答案

before后加动词是吗形式?before可以用作【连词】和【介词】用作【连词】时,后接【句子】.用作【介词】时,后接【名词】或【动名词】.如：Before he arrived, we had finished the work.(连词) Before his arriv...