Could you also use genitive here, like "buy some chocolate"?
That's a really old question but lemme answer that for new people wondering the answer. I'm nowhere near the mastery of russian but i think да, you can.
Пожалуйста, купи шоколада? should work
Cool - in Hebrew it's also שוקולד/shokolad!
Ever notice the similarities between ш and ש?
That's because they're both ultimately derived from the Phoenician letter shin. You might notice that they also look pretty similar to Arabic س and Greek Σ (albeit rotated).
It took me a while to realize this so I'll note it here
купи is the IMPERATIVE I believe
(don't try and look up the present or future tense of "to buy" or you will lose much time!)
Can one say "Пожалуйста, купите шоколад" instead?
Yes, your choice is right. If it is not accepted, report it next time you will come across this task.
What's the difference between купи and купите? like is one of them plural imperative?
Купите is the plural imperative but could also be the formal singular.
Yes and more:
Ты Купи - singular imperative informal
Вы купите - singular imperative formal, and plural
This is a nice link to get conjugations:
I know that "Купи шоколад пожалуйста" is also accepted but I keep wondering which one would be "used in a real scenario".
Can anyone, please, give some insight into which one would be more commonly used and why?
Can the perfective form, покупать, be used? So, 'покупай/покупайте шоколад, пожалуйста.'
"Покупать" is actually the imperfective verb. "Купи" is perfective. Yes, it's different from the usual pattern, but it happens.