---You used to be short,you ---Yes ,I .

题目

---You used to be short,you ---Yes ,I .
---You used to be short,didn't you?---Yes,I did.

---You used to be short,usedn't you?---Yes,I did.
---You used to be short,usedn't you?---Yes,I used to.
---You used to be short,usedn't you?---Yes,I used.

答案

你标题上的那句答语不完整,不知是否是你打掉了,如果就是这样,当然不对
最后一句也不对,中间的全对.
used to可以看成半情态动词,也可以看成实义动词
当看成情态动词,可以用used to回答,此时不可省to
当看成实义动词,应该用助动词来替代.
回答完毕,如果有疑问,可追问,如满意,请采纳.