Finally something useful!
кошки sounds pretty funny when played just by itself.
Why is it they're and not their?
Because they're is a contraction of they are, and their means "belonging to them". They aren't synonymous.
Они кошки means they are (they're) cats. Their cats (the cats that belong to them) would be их кошки.
"Кот" means male cat and "кошка" female? Idk °^°
Should we not write они - кошки to indicate "are" ... verb "to be"
Yes, you are right. Omitting the dash is a common mistake in modern Russian tending to become a new rule of the language.
The dash is not normally used when the subject is a pronoun (e.g., Мы друзья or Я Вася). You can include it, of course (it would just imply that the intonation is dramatic).
That's right, my fault, sorry. Thought of it like in "У них по девять жизней. Они - кошки." Without a context, the dash is not needed by default.
Does that sentence have another conotation? In portuguese, if you call someone a cat it means the person is beautiful
Kind of. It just isn't exeptionaly common.
How I can write in russian with this words
Install a Russian keyboard extension on your phone's keyboard app
Why is они кошки (no cap, no full stop) wrong and why is there no "my solution should be accepted" option?
Они не собаки?