might he do it or not

[navi tasan]

Can one say:
1-Might he do it or not?
instead of:
2-Is there a possibility that he might do it or isn't there?

Can one say:
3-Must he go out or not?
instead of:
4-Does he have to go out or not?

[5jj]

Can one say:
1-Might he do it or not?...instead of: ...2-Is there a possibility that he might do it or isn't there?

One can

Can one say:...
3-Must he go out or not?'''instead of: ..4-Does he have to go out or not?

One can.

For me, the most natural forms would be:
Is it possible that he'll do it, or not?......Does he have to go out, or not?