Let's change the subject.
Let's talk about something else.
Let's talk about something different.
I'd rather talk about something else.
Let's get back to the subject.
Let's get back to the point.
Let's get back on track.
I don't want to talk about it now.
I'd prefer not to talk about it.
Let's talk about it later.
We're playing golf this Sunday, right?
To change the subject...
I can't believe it.
Well, all joking aside,...
Ha, ha, that's a good one!
Well, all joking aside, let's get to work.
By the way, how is John?
You were saying? *说话过程中话题改变时。
Continue. Carry on.
Please go on.
Oh, that reminds me. I can't go. (啊，我想起来了，我去不了。)
Let's stop talking.
I'm tired of talking.
I don't want to talk anymore.
I've heard the story before. *用于对方重复说一件事时。
You've already told me.
I'm sick and tired of hearing that. *sick and tired of... “对……腻透了“。
I've heard enough about it (already).*加already起强调作用。
I don't want to hear about it anymore.
Let's drop the subject. *drop 除了“落下“之外，还表示“(问题、事件、话题等)完了、结束、停止“。
Let's drop it.
I don't want to talk about it anymore.
Don't say it so loud.
I thought you were hard of hearing.
Don't say that kind of thing so loudly.
(Please) lower you voice.