I put "I am singing in September." It was accepted, but I'm wondering if Norwegian uses the present-as-future tense phrasing like we do in English (i.e. "I am singing in September" really means "I am going to sing in September") or if my answer actually should have been rejected.
This is an affirmative sentence. There is an inversion of verb and pronoun because the verb always have to be the second element of the sentence and not because it is a question. The sentence starts with "I september" which is element number one. "synger" is element number 2 and "jeg" is element number 3. Therefore this is an affirmation and not a question (not sure if I'm using the correct grammatical terms). So to be a question it'd be like Sapiophia said.