[Romulus]

In what language is “out” a preposition?

[rjsimmon]

When there is an implication of a continuation.

out

/out/
preposition
49.(used to indicate movement or direction from the inside to the outside of something):
He looked out the window. She ran out the door.

50.(used to indicate location):
The car is parked out back.

51.(used to indicate movement away from a central point):
Let's drive out the old parkway.