Is there any variation of this with 'maybe'? That is the meaning of this I was taught in a Polish course. I suppose possibly and maybe are similar, but it didn't go for my maybe sentence.
The better equivalent of "maybe" is „może”. With „chyba” you are not 100% sure, but enough to make a prediction. With „może” you are more expressing a possibility, which might be true, but you are not so sure either way.
Może być, ale nie musi. Do zdania "It is not a cat" słowo "probably" pasuje według mnie na początku, po pierwszym słowie, po drugim słowie oraz na końcu.