Hello Alina,
Both are grammatically correct.
Either one can be used in the same situation.
Is it a mistake?
No, it's not a mistake.
No, it isn't a mistake.
No, it's not.
No, it isn't.
These are all good.
8 Şubat 2016
1
3
Hâlâ cevap bulamadın mı?
Sorularını yaz ve ana dil konuşanlar sana yardım etsin!