Film is a masculine noun in Bokmål. Its common forms are:
Norwegian often uses the present to state general truths or habitual actions, and to talk about the future in time clauses. Barna gråter når filmen slutter is natural. You could predict the future with expressions like kommer til å or vil, but you still typically keep present in the time clause:
Use the past and switch to da:
Use hvis or om for “if.” Når means “when.”
Yes, with slight nuances:
Norwegian usually uses the simple present for ongoing actions: Barna gråter = “The children are crying.” To highlight the ongoing aspect, you can use posture + “og”:
Yes:
Not when the subordinate clause comes after the main clause, as in your sentence—no comma is needed. If you front the time clause, you do use a comma:
Yes. Use the indefinite plural for “children” and an indefinite for “movie”:
You can, and it’s common in spoken Norwegian for emphasis or rhythm. In careful writing, it’s usually omitted: