惯动作或状态，这种情况现已不复存在。例如：
He used to smoke a lot， but he has long given up smoking.
在否定陈述句或否定疑问句中，用didn t use to或used t to均可：
He didn t use to smoke cigarettes.
He used t to smoke cigarettes.
Didn t Maria use to be interested in the theatre？
Used t Maria to be interested in the theatre？
在肯定疑问句中也可有两种形式：
Used you to go to the same school as Edward？
Did you use to go to the same school as Edward？
近义词辨析
use， apply， avail， employ， utilize
这组词均含有“使用”或“利用”之意。
use
强调利用人或物作为工具。
He used up all his resources in experimenting with the new paint.他为实验新的涂料，花光了一切钱财。
apply
指把某物或某种方法、原理等加以应用。
We should not only know the theory but also know how to apply it to practice.我们不仅要知道理论，还要知道怎样把理论应用于实践。
avail
指使用就近的或他人给予的东西，或使别人为自己提供服务。
I don t think complaints will avail you much.我觉得抱怨对你没多大用处。
We avail ourselves of every opportunity to speak English.我们利用一切机会讲英语。
employ
指使用未被利用的东西；用于人时表示雇用。
He does t know how to employ his energy and time.他不知道该怎么利用他的精力和时间。
utilize
指充分发挥某物的作用，使无用的东西变有用，或使人或物有新用途。
She hopes to utilize her artistic talents in the job.她希望在工作中发挥她的艺术才能。
