I wonder since when it has been like this,为什么since后的那个句子是用完成式-myfoot hurts terribly,doctor.-I wonder since when it has been like this?since后都是加时间点,也就是过去式,可是为什么这里的since后加的句子是完成时呢?我认为since是个介词,所以后面的所有都是做since的宾语从句呀,可是为什么会是完成时呢?

问题描述:

I wonder since when it has been like this,为什么since后的那个句子是用完成式
-myfoot hurts terribly,doctor.
-I wonder since when it has been like this?
since后都是加时间点,也就是过去式,可是为什么这里的since后加的句子是完成时呢?
我认为since是个介词,所以后面的所有都是做since的宾语从句呀,可是为什么会是完成时呢?