It sounds like there's an extra syllable on the end of 'Professor' here. Anyone else hear that?
EDIT: Or is this a case of consonantal 'r'?
No, I definitely heard it too - it almost sounded like it was saying Professorin, but that obviously makes no sense witht he article of der. I had to play it slowly to make sure that it wasn't meant to be there.
I heard it too. The slow version is unambiguous, but the regular speed one definitely glitches at the end of 'Professor'.
What about "teaches" or "is teaching"? Is always thought lernen is both, to learn and to teach in German. Especially in this context, I would guess that a professor teaches someone, not is being taught.
The professor teaches German would be in German: Der Professor unterrichtet Deutsch.
"Professor" means "professor" and nothing else. The German for "teacher" is "Lehrer" (primary/secondary school) or "Dozent" (university).
I contest that. I learnt (from a native German speaker) at school that Professor is also teacher AND Duolingo dictionary gives gramma school teacher as an option.