은 아니겠지

it can't be

→ 은
phrase Uncommon #10,388
it can't be Used to express doubt or worry that something is probably not true. Often ends a sentence as a rhetorical question.
KO: 설마 농담은 아니겠지?
EN: This isn't a joke, right?

아직은 아니겠지

Not yet, right?

— 엠 (1931)

나 때문에 그런 것은 아니겠지

It’s not because of me, is it?

— 음식남녀 (1994)

나까지 속일 작정은 아니겠지?

You're not planning to fool me, are you?

— 캐치 미 이프 유 캔 (2002)

진심은 아니겠지?

You don't mean it, do you?

— 아틀란티스: 잃어버린 제국 (2001)

함정은 아니겠지?

It's not a trap, is it?

— 안드레이 루블료프 (1966)

신경 발작은 아니겠지?

It's not a nervous breakdown, is it?

— 아메리카의 밤 (1973)