Use of A/An/The ...... Articles

If some one asked you if you have any pets, you reply "Yes, I have a cat".
If some one else asked you how many cats you have, you reply "I have one cat". or, "I have one".

Ile kotów masz?
Mam jeden kot. And it is just as well! :-)

https://polishforums.com/language/plural-forms-cztery-kubki-czternascie-kubkow-52737/#msg1149468

Ile kotów masz?
Mam jeden kot. And it is just as well! :-)

Rather..... : Mam jednego kota. Just as well :-)

Because it is a male animal and not a mug?! :-( Next time I will get it right hopefully. Some say there that you learn from your mistakes! :-)

What would you say if I had 2, 3, 4 or 5 cats?

Numbers are tricky.

Mam jednego kota....
Mam dwa koty
Mam trzy koty
Mam cztery koty
Mam pięć kotów
Mam sześć kotów, etc.

but....

Mam czterdzieści jeden kotów
Mam czterdzieści dwa koty (3 & 4 = the same form applies)
Mam czterdzieści pięć kotów, etc

Let's just assume you will not have more than five cats in any case. :-) However, even then 3 different declension patterns apply.

Many thanks, that was a great help.