I used to smoke, but I have quit.

我曾经吸烟，现在已经戒了。

youdao

I have quit smoking.

我已经戒烟了。

youdao

In the past 12 months I have quit one job and found another that I enjoy much more.

在过去的12个月里，我辞掉了一份工作，找了一份自己更喜欢的工作。

youdao

The truth is, if I had adopted an extreme exercise regimen with Robert, and then stopped being able to go, I would have quit completely without his encouragement.

CNN: Paging Dr. Gupta Blog

Do I have to quit my job?

CNN: Occupational asthma

Since I have never been one to quit, I decided that the best course of action was to remain here and fix the problems.

CNN: Gonzales says he's keeping his post, wants to 'fix problems'