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!
So "kolega" is masculine?
Yes. The feminine version is "koleżanka".
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".
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".