查字典中考网整理了关于2020年中考英语知识点之一般过去时肯定句变为否定句，希望对同学们有所帮助，仅供参考。
肯定句变为否定句
技巧1：
当句中含有情态动词或助动词could，would，should等时，可直接在其后面加not构成否定句。例如：
I could get you a concert ticket. I could not / couldnt get you a concert ticket.
技巧2：
当句中含有系动词was，were 时，可直接在其后加not构成否定句。例如：
I was on the Internet when you called me. I was not / wasnt on the Internet when you called me.
技巧3：
当句中谓语是除情态动词、助动词、系动词was,were以外的动词时，在该动词之前加did not / didnt，动词还原，构成否定句。例如：
The famous singer sang some Chinese songs. The famous singer did not / didnt sing any Chinese songs.