Why is "teacher" in the indefinite rather than in the definite form, i.e., "Han er skolens mest populære læreren"
It's indefinite in the English sentence as well.
So if there is indefinite form, why is there "populaære" instead of "populær"?
English only inserts the definite article when the word order is reversed: "He is the school's best teacher" or "he is the best teacher of the school." Either way, the only true definite here is 'school'.
Is there any difference in the pronunciation of e and et when they end a word?
Why populære when the noun is indefinite?
He is the teacher.
He is the [most popular] teacher.
I hope that helps. :0)