一、Used to表示过去的习惯动作或状态，现在已不存在，在间接引语中，其形式可不变。如：
1.He told us he used to play football when he was young.
他告诉我们他年轻时经常踢足球。
2.I weigh less than I used to.
我的体重比以前轻了。
3.He is used to eating out all the time.
他已经习惯在外面吃饭了。
4.You'll get used to it.
你会习惯的。
5.Are you used to the food here?
你习惯吃这儿的饭菜吗？
6.I used to get up early and take an hour's walk before breakfast.
我过去常常起床很早并且在早餐前散步一小时。
7.Women used to think they were on the shelf at 30.
过去女人一到30岁就认为是过了结婚年龄。
8.Jack used to assist Mary in her lessons.
杰克过去常常帮助玛丽学习功课。

二、在疑问句、否定句、否定疑问句或强调句中，可有两种形式：
1、疑问句
Did you use to go to the same school as your brother?
Used you to go to the same school as your brother?
2、否定句
I usedn't to go there.
I didn't use to go there.
3、否定疑问句
Usen't you to be interested in the theatre?
Didn't you use to be interested in the theatre?
4、强调句
I certainly used to smoke,but it was a long time ago.
I certainly did use to smoke,but it was a long time ago.
5、其反意疑问句或简略回答中，也有两种形式：
She used to be very fat,didn't she? （口语+常用）/ use(d)n't she? （正式+过时）
Did you use to play chess? Yes,I did.
Used you to get up early in the morning? Yes,I did. (Yes,I used to.)