So how do I distinguish between fra and tra? Are there rules when we should use one rather than another?
"tra" and "fra" are interchangeable since both mean the same thing "between".
There is only one "rule" that I know of and it says : Use the one which sounds better in the sentence.
Probably the only rule is to avoid similarly sounding words like: "between brothers" - "fra fratelli" - grammatically good, but silly, so you should use "tra fratelli".
I have never known there to be feminine forms of "cat". But DL finds "la gatta" and "le gatte" acceptable. DO these forms actually exist? And would I use them to indicate the cat's sex? What about other animals?
that is if you know they are all female, if even one is male then it is 'gatti'
To be precise
il gatto = the male cat
la gatta = the female cat
i gatti = the male cats
le gatte = the female cats
Why is he between the cats?