Which one of these combinations are correct :
(1) On se voit quand t'es libre.
(2) On se voit quand tu seras libre.
(3) On se verra quand t'es libre.
(4) On se verra quand tu seras libre.
Sometimes I heard people use one and sometimes another. In English I think we only say either of the two options :
We see again when you are free. -> This is less frequently heard
We'll see again when you are free.
without future tense in the second phrase after "when".
Just for confirmation : Is it true we never say the following ? And why ?
On se verra quand tu vas être libre.