So "kolega" is masculine?
Yes. The feminine version is "koleżanka".
Is the Instructive case of "kolegą" being determined by "jesteś" or "moim"?
kolega determines number and gender of adjective(pronoun) mój -mój kolega
Jesteś -needs Instrumental and determines the case of noun kolega -kolegą, and adjective (pronoun) mój kolega- moim kolegą
Instrumental, not locative.
Of course Narzędnik= Instrumental
I fail every time I try to name a case in English without help :(
I know that feel. Before I found Duolingo, I couldn't remember English names for Celownik (Dative) and Biernik (Accusative).
Let's just use akuzatyw instead of biernik!
Is co worker only kolega z pracy? Because colleague is a coworker in most cases?
Frankly, a better translation of 'kolega' is actually 'friend', as English doesn't make the distinctions that Polish does... 'kolega' is just not one of your closest friends.
So a kolega is closer than a znajomy but not as close as a przyjaciel?
There's always some degree of subjectivity in the way people use words, but I would say so.
When do I use "moim"?
It's the Instrumental of "mój". As "to be" needs a noun phrase to be in Instrumental, "mój" has to adapt and "mój kolega" turns into "moim kolegą".
Colleague and kolega are false friends as only the word kolega signifies a friend or acquaintance whereas you have to specify that it's a work friend for it to mean colleague (kolega z pracy).
Source: my Polish girlfriend.
Well, they may overlap a bit, but generally I agree. I changed the main translation to "friend".
Both ‘you are’ & ‘are you’ are normal English versions of the same question, with the voice-uptick at the end. Reported.
Added "you are".
In which case is kolegą?
Instrumental, as needed by "jesteś".