used to do sth.句型表示“过去常常,过去习惯.”表示过去的某种习惯(过去经常反复发生的动作或状态). e.g.I used to live there when I was a child. 否定式：used not to do sth. 口语中：didn’t use to do sth. (used not可缩写为usedn’t或usen’t.) e.g.I used not to live there when I was a child. I didn’t use to live there when I was a child. 疑问句：used sb.to do sth. Did sb.use to do sth. e.g.Used you to live there when you was a child. Did you use to live there when you was a child? used to do sth.与be used to (doing) sth.的区别 1.used to do sth.“过去总做某事”(现在不做了)只用于过去时态. e.g.He used to get up early. 2.be used to (doing) sth.表“习惯于做某事”,可用于现在、过去、将来的多种时态,be可以用become,get等来代替,此处to是介词. e.g.He will be used to getting up early. 本文来源：https://www.wddqw.com/doc/41e19dba132de2bd960590c69ec3d5bbfc0ada7a.html