used 一分为二 第一种 把used 看成情态动词 那么否定就是直接在情态动词后面加not, 疑问就是把used 提前 否定形式就是 used not to do =usdn't to do 疑问形式就是usedto do 第二种 把used 看成是use的过去式,也就是句子为一般过去时 那么否定就是didn't use to do (一般过去时的否定就是did not +动词原形) 疑问形式就是 diduse to do (一般过去时的助动词did提前,那么use应该用原形)
加 d 是use to to 的形式
eg.1.She used to be lazy.对lazy提问,就可以说: How did she use to be?2.He used to work in a factory.对work in a factory提问,就可以说:What did he use to do?总之呢,就是:特殊疑问词【how,what,where,when等等(具体要看问什么)】+ did + 人称代词 + use to + 句子剩下的部分 .
肯定回答是:主语+ used to + 动词原形.比如: 问:What did you use to do in the evening? 答:I used to watch TV.
I/he/she/we/it used to do sth.
否定句疑问句usedn't to do 过去常常used to do sth 过去习惯be used to (doing) sth
1、be used to doing I am used to staying late into night. 我习惯于熬夜. Are you used to staying alone at home . 你习惯一个人待在家吗? What is he used to doing? 他惯于干什么? He was used to smoking, wasn't he? 他养成了吸烟的习惯 ,
过去时
diduse to do