一般过去时的句法结构：
1、肯定形式
主语+动词过去式+其它
例句：She came to help us in those days．
2、否定形态
主语+didn't +谓语动词原形+其它
1.在行为动词前加didn't，同时还原行为动词
例句：I didn't know you like coffee.
3、一般疑问句
①Did+主语+谓语动词原形+其它
②Was/Were+主语+表语
例句：Did you do homework?
4、特殊疑问句
特殊疑问词+ did+主语+动词原形+其它？
特殊疑问词+was/were+物主代词/...'s+sth.？
5、被动语态
主语 + was / were + 动词的过去分词