Is this really the way to show future tense, or does it have a slightly different meaning? It seems a bit early in the course for it.
It's a really random place to put it without any explanation.
The most usual way to make a future tense is with θα. Θα comes from θέλω ίνα, I am going to that transformed to θέ νά and finally θα. Since θέλω means I want, it is not so different this itinerary from the English furure as will comes from the same verb. There are other ways to express future in Greek, as πρόκειται να, I am going to. The present tense can be used too with the meaning of future, or past tense, depending on the context or a time adverb, i.e. έρχομαι (στην) Αθήνα αύριο, I will go to Athens tomorrow.
Thnk you for
That's what my friends tell me in a bar after ordering shots and after I've had enough to drink...
This is future continuous and the correct translation is "you will be drinking". If you want to say "You will drink" the translation is "Εσύ θα πιείς" or "Θα πιείς"
'You are going to be drinking' would be accurate enough I think. This is a future progressive example.
Indeed this is future progressive. Progressive or not depends only on the verb. Future tenses always have "θα".
My Greek girlfriend says that this is future continuous and for simple future she would use something else. How does it work then?
It's a kind of exercise very interesting but sometimes it's confusing me 'cause it has these letters very different. But reference to this sentence I thought that's was gonna be more complicated