Explanation of 'θα'
I am somewhat familiar with words and phrases using the word θα, and know its basic function (i.e., it is placed before verbs in the present tense to create the future), but I would like some further explanation of it. Is this its only function? How else is it used? Are there alternatives? Is the future tense actually this simple?
For instance, in a sentence like, Θα είμαι εκεί αύριο (I will be there tomorrow), if you removed the word θα, what kind of sentence would that be, since you can't actually make it into present tense?
I mean, what does that translate to? "I am there tomorrow"?
If someone knowledgable in Greek could give me a (hopefully extensive) explanation on θα (in general), it would be much appreciated.
Native speaker here, but not a teacher, so i will give this my best shot.
You got the basic idea. Θα indicates the will to do something (as "will" in english) but also the fact that is definitely the case.
Θα είμαι εκεί αύριο indicates that you are going to be there tomorrow, for sure, that is your plan.
Without the θα it would sound like a more generalization, and my intuition says that there should be some kind of context before (at least maybe it sounds better that way). Think about it like in english
I will be at the supermarket tomorrow - Θα ειμαι στο σουπερμαρκετ αυριο. I'm at the supermarket tomorrow - Ειμαι στο σουπερμαρκετ αυριο.
Please not that without the θα , the sentence can also be present tense. So its a good way to show future, without using other keywords (tomorrow, later, soon etc).
Θα ειμαι εκει που με αφησες - I'll be there where you left me (in the future) Ειμαι εκει που με αφησες - I'm there where you left me (right now)
But in the example you gave and my first example, the tomorrow part already indicates future, so removing the θα still shows future intent (the tomorrow just specifies exactly when).
Hope this helps somehow!
Θα didn't exist in Ancient Greek. In the Hellenistic period, that is about the centuries of the period of Christ, after Alexander the Great, It started being used a form of it in the phrase θέλει ίνα... that is "it is going to" and next θένα and finally θα. This periphrastic future is similar to the English "will". So the separate tense of Future in Ancient Greek disappeared. But as you know there two futures now, the simple and the continuous one. You can also use the periphrasis πρόκειται να..., Or even the present to express future, αύριο φεύγω για (την) Αθήνα. But this is another question. :)
You can actually remove θα only when it's future continuous, and it becomes present tense:
θα τρέχω στο δρόμο - I will be running down the road
τρέχω στο δρόμο - I am running down the road
But when it's simple future you can't remove θα, the verb can't stand alone:
θα τρέξω στο δρόμο - I will run down the road
τρέξω στο δρόμο - >>> incomplete, doesn't make sense <<<
Θα can also mean "would" when followed by a verb in past continuous:
Θα ήθελα έναν καφέ - I would like a cup of coffee
Τι θα έλεγες αν έφευγα; - What would you say if I left?
Here is θα introduced in the Complete Greek language Transfer tracks, quite useful I think: