She was in that great action movie last month.

问题描述:

She was in that great action movie last month.
其中的was怎么理解,有什么语法?

was是be动词,也是谓语动词,这里用过去式的原因是因为时间状语last month是一个过去时间
这里 in that great action movie 是做was的表语,构成系表结构.