Colloquial, and professors hate being called "prof" by the way...
But the English says 'teacher' not 'professor', there is a difference
"le prof" can also be correct...
I wrote "enseignante" and it was marked incorrect?
"enseignante" is accepted provided the rest of your translation is correct as well.
"Le enseignant mange une orange" was not accepted.
"le" and "la" have to elide in front of a word starting with a vowel sound:
Oh, of course. Thanks.
I've lived in France, isn't "instructeur/instructrice" also correct?
can the word "professeur" be masculine and feminine?
Oui, un professeur (no feminine version).
why not ''la professeur''?
This noun only exists in masculine.
so am i to refer to a woman with ''le professeur''?
Oui, but context would tell that the teacher is a "she" : "madame le professeur XX" or "la femme professeur" or "le professeur femme", for example; otherwise, a larger context will most probably use "elle" at some point.
ok, thanks for the clarification!