was和were后面加动词的什么形式?在什么时候要加原形,什么时候加动词ing

Question

was和were后面加动词的什么形式?
在什么时候要加原形,什么时候加动词ing

Answer 1

答：它们是be动词的过去式
一、作助动词：
1.　现在分词,构成过去进行时态：
He was reading.
2.过去分词,构成被动语态：
They were defeated.
二、作系动词
3.　现在分词、动名词短语作表语：
　　The film was moving.
His job was teaching English .
4.　过去分词作表语：
　　We were moved.
5.不定式作表语：
　1）有to不定式：His work that day was to clean the blackboard.
2) 无to 不定式：What he should do is clean the blackboard.