不是在

isn’t [someone or something] in/at…?, not be doing (something)

→ 不
phrase Rare #15,475
isn’t [someone or something] in/at…? Used in a negative question about a place, often to check or expect confirmation that someone or something is there.
CH: 你家不是在台北吗?
EN: Isn’t your home in Taipei?

是啊,我刚不是在…

Yeah, wasn't I just...

— 维多利亚 (2015)

他不是在长滩吗

Isn't he in Long Beach?

— 双重赔偿 (1944)

妳父亲不是在英国吗?

Isn't your father in the UK?

— 色‧戒 (2007)

你家不是在台北吗

Isn’t your home in Taipei?

— 那些年,我们一起追的女孩 (2011)

phrase Rare #24,575
not be doing (something) Used before an action verb to say that the action is not in progress. The exact English wording depends on context.
CH: 我不是在开玩笑。
EN: I’m not joking.

我们不是在工作吗?

Aren't we working?

— 阿玛柯德 (1973)

很明显你不是在摔跤

Obviously, you're not wrestling.

— 摔跤吧!爸爸 (2016)

你不是在告解

You're not at confession.

— 利维坦 (2014)

反正不是在争吵

At least we're not arguing.

— 坠落的审判 (2023)

我们也不是在玩耍

We’re not playing around either.

— 风之谷 (1984)