2013年12月大学英语六级考试语法解析17
2013年12月大学英语六级考试语法解析17
主动语态(以 do 为例:)
过去
现在
将来
过去将来
一般
did
do
will/shall do
would / should
do
进行
was/were doing
am/is/are doing
will/shall be
doing
would / should
be doing
完成
had done
have/has done
will/shall have
done
would / should
have done
完成进行
had been doing
have/has been
doing
will/shall have
been doing
would/should
have been doing