中文翻译成英文 “劝他们赶快戒烟吧”

Try to persuade them to give up smoking immediately!

Persuade them to give up smoking soon.

戒烟常用quit

Urge them quickly to give up smoking.

Advise them to give up smoking quickly

汉语是个无主句，但很显然主语可以说是“我”。英语很少用无主句，少数时候比如写日记之类的才会出现。

I advise that you give up smoking quickly.