The sign for "future" is made by slicing a "flat hand"
forward through the air. The farther you move your hand, the further
into the the future you are referring. This sign can also mean such
things as "WILL" as in, "Will you go to college?" (YOU FUTURE COLLEGE YOU?).
You can also use a double arching movement to mean "someday" or "the distant
future." If you do a single large strong movement it can mean "a long
time from now."
"Do you think someday you will teach ASL?"
Far in the future:
Use a bigger movement that goes farther.