because first is in nominative and other in genitive-in this case implies possesion, Think of my enemy's enemy, enemy =wróg, my enemy's= mojego wroga. also przyjacielem is instrumental form of "przyjaciel"
What got me on this one was that I left out the "of" .....other than deducing that it makes sense to put "of" in this sentence, and it's a known saying...how would I know to do that? Just trying to understand so that in future cases I'll know what to look for.
Well, I guess that mostly you just need to remember about correct English syntax. Some things just don't have an equivalent. Although using Genitive for "mojego wroga" already suggests there may be some "of".
Would this sentence really use przyjaciel, because the translation specifies that it means close (personal) friend. Would kolega or towarzysz work better with the sense of the expression? I am just trying to get a better sense of the native usage.
Hmmm. It's true that generally "przyjaciel" should be a close friend, but somehow I can't imagine any other word in this sentence. Any other is just not enough. Well, this sentence is an idiomatic exaggeration anyway...