一般过去时三种句型形式 肯定形式： 主语+动词过去式+其他 例句：She often came to help us in those days. 否定形式： ①was/were+not;②在行为动词前加didn't，同时还原行为动词 例句：I didn't know you are so busy. 一般疑问句： ①Did+主语+do+其他? ②Was\Were+主语+ do sth? 例句：Did I do that?