As she was reading the newspaper,granny felt asleep

问题描述:

As she was reading the newspaper,granny felt asleep
为什么as用一般过去时?

as不是动词,没有时态问题.
as从句是过去进行时,主句是一般过去时.
表示过去的一种伴随状况:她看报纸时,granny睡着了.
句中的as也可换成when.