★变否定句在be动词后面加not
I was not at the butcher’s.
You were not a student a year ago.
The teacher was not very beautiful ten years ago.
★肯定回答否定回答
Yes, I was. No, I was not.
Yes, you were. No, you were not.
Yes, he/she was. No, he/she was not.
★特殊疑问句：
What did you do?
(必背)
不含有be动词的句子，将动词变为过去式，动词过去式构成见附录
I finished my homework yesterday.
The boy went to a restaurant.
The Sawyers lived at King Street a year ago.
★变疑问句在句首加did， 动词变为原型
Did you finish your homework yesterday?
Did the boy go to a restaurant?
Did the Sawyers live at King Street a year ago?
★变否定句在主语和动词之间加did not
I did not finish my homework yesterday.
The boy did not go to a restaurant.
The Sawyers did not live at King Street a year ago.
★肯定回答及否定回答
Yes, I did. No, I didn’t.
Yes, he did. No, he didn’t.
Yes, they did. No, they did not.
4. 现在完成时
构成：主语+助动词have, has+过去分词
用法：
2) 表示过去发生的和现在有某种联系的动作，常和just, usually, already, since等时间副词连用
I have just had lunch. (饱了，不用再吃了)
He has had a cup of tea.（不渴了，不用再喝）
They have already had their holiday. （不能再度假了）
The boy has already read the book. （已经知道书的内容了，不用再看了）
3) 询问别人是否做过某事一般用现在完成时：
Have you finished your homework?
Have you been to Beijing?
Have he seen the film?
4) 表示开始于过去并持续到现在的动作
I have lived in Beijing for twenty years.
I have worked for this school for 1 year.