結構形式：
肯定形式
主語+動詞過去式+其它
例句：She came to help us in those day．
否定形式
主語+didn't+謂語動詞原形+其它
①was/were+not；②在行為動詞前加didn't，同時還原行為動詞
例句：I didn't know you like coffee.
一般疑問句
①Did+主語+謂語動詞原形+其它②Was/Were+主語+表語
例句：Did I do homework?
特殊疑問句
疑問詞+did+主語+動詞原形+其它
疑問詞+was/were+物主代詞/...'s+sth.