θα + imperfect tense is used to make the conditional.
μπορούσα = I could (indicative, simple past); I was able to
θα μπορούσα = I could (conditional); I would be able to
Or to take a verb where the distinction is clearer in English:
ήθελα = I liked
θα ήθελα = I would like
It seems like there were no Tips and Notes for Modals in the first tree :/
In the second tree, we moved some of the lexemes of the modals and moved them to one Conditional skill (because we figured that, just like the Gerund, the term Modals doesn't really make sense in Greek). The Tips and Notes there are the same with the ones in the Conditional skill of tree 1, the very last skill of the course. They aren't extremely useful, they are certainly helpful, to some extent.
Rewriting all Tips and Notes is a process that takes quite a bit of time, and Conditional is one of the last grammar skills. Please, bear with us while we edit them. We do apologize for any inconvenience that is caused by the lack of Tips and Notes at this stage. Thank you for your comment, and your patience! ^.^
(Of course, when Tips and Notes for a skill are reedited, you won't have to wait until the next tree is released, if there is a corresponding skill in Tree 1. All additions become available in tree 2, but also tree 1, whenever that's possible.)
The conditional tense only really makes sense with another clause e.g. "If I were driving (subjunctive), I would not (conditional) be able to drink". Or in reported speech, "the man said that he will (future) not be able to drink" ......becomes " the man said that he would ( conditional) not be able to drink".
If you see Lyazko's comment above, the phrase means "I would not be able to drink wine". It is not a simple future tense sentence. See also mizinamo's reply to mcampanella.
Μπορώ = I can, I am able (present)
Θα μπορώ = I will be able (future= Θα + present)
Μπορούσα = I was able (past continuous)
Θα μπρούσα = I would be able (Θα + past continuous)
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