Are they equivalent? Or is o used only in the accusative case, perhaps?
To me this was one of these "where in the world did that come from" moments that exist in all trees, especially in the first few skills. It's actually pretty amazing that it's the first one i encounter, for such a fresh beta! But it might be worth more specific introduction or a line in one of the lesson's tips and notes (I actually got thrown of here by half remembering the tips and notes from "food", where 'o' is used but as he/she)
In fact, difference between "bu" and "şu" & "o" is quite clear (Selcen stated at the very beginning) but we cannat say that one is closer and other is farther between "o" and "şu". Not a grammatical rule but as a feeling "şu" is usually somehow more negative than "o" and always far. We sometimes use "o" for objects (or persons) which is not far away for just pointing. For example when we are sitting next to each other and chatting you can say "O kahveyi içecek misin ?" = "Will you drink that coffee ?". On the other hand (it is not a rule as I said before) if I am angrya t you and want you to drink that coffe same sentence can be "Şu kahveyi içecek misin ?" It is some how like scolding. In same cases if the object (or person)that we are pointing out is not clear (when I am trying to tell you which one I am talking about) we use "şu" (frequently with a finger pointing toward :P) rather than "o"
No, there is no such rule. Bu/Şu and O can all be used both with a subject and with an object. When speaking the use of "şu" is just a feeling. It can both mean "bu" and "o". It's not a very black and white thing. It depends on the vicinity of the object, the vicinity of another similar object with which you're actually making a contrast, the fact that the said object has already been mentioned so you're perhaps making a reference to that, position of the listener and so on. It's a bit vague. And you don't have to master it for intelligibility at this level. Give it some time. It'll come natural to you at one point. However, one solid rule when writing, is that "şu" is used when you're about to introduce a new thing, while "bu" is used when you're referring to something you've mentioned. For example: "Şu tablo…" means "the following table", I still haven't showed you the table, I'm doing it now. And when you say "bu tablo…", it's best translated as "The table above", because you're referring to a table that you've just showed us.
the sentence would then be gramatically incorrect. Coffee (or that coffee or this coffee or any other coffee) is direct object of this sentence, so it has to have that suffix. O kahve just means "that coffee" (in nominative - subject case). O kahveyi means "that coffee" (acusative - object case).
So, "sen o kahveyi içersin" = "I drink that coffee", while "sen kahveyi içersin" = "I drink the coffee?" Does "o" determine whether the sentence is this or the?
Firstly the meaning is you drink not i drink
O khave here means that coffee as if u are pointing to a specific cup of coffee, and because we are speaking a bout a specific coffee we have to use accusative which by its own reflects a specific objects. So even if u are omitting O and using accusative suffix this means a specific object as in ur second sentence
Hope this helps
Whoops— meant to say 'you.' Thank you, though! That cleared it up a lot.