used to/juːst tʊ/

v. used to say that sth existed or repeatedly happened in the past but does not exist or happen now

否定缩略式

➭ usedn't/'juːsənt/

v. [M] 过去常常，过去习惯：He used to smoke. 他过去常吸烟。

◇Did he use（或Used he） to smoke? 他过去吸烟吗？

◇[did not use to do sth = used not to do sth] He did not use to smoke. = He used not to smoke. 他过去不吸烟。

常犯错误

✗ Did he used to work here?

✓ Did he use to work here?

✓ Used he to work here? 他过去在这里工作吗？

用法反义问句部分可用didn't he或usedn't he。