Question

used to do要加动词原形才能构成吗

Answer 1

used to do要加动词原形才能构成。

used to表示过去经常做某事，但现在不做了，后面加动词原形。即：used to do sth。

这条河以前是干净的。The river used to be clean.

从前这里有一家餐厅。There used to be a restaurant here.

吉姆过去经常踢足球，但是现在他年龄太大而不再踢球了。Jim used to play football, but now he is too old to play it.

The soldiers all used to do a six-month tour of duty in Northern Ireland.

士兵过去都要在北爱尔兰服役六个月。

I used to do that when you were a little girl, remember?

在你还是小女孩的时候我曾经那么做过，记得吗？

Potential energy can be used to do work.

势能可以用来做功。

The lecturer used to do well, but he seems to have gone off now.

这个讲师以前挺好，但如今似乎讲得差了。