"She understands the teacher."
Translation:Ela entende o professor.
Can you also say "Ela entende ao professor" or is the "a" not necessary the way similar things are needed in French and Spanish? Also, is compreender used interchangeably with entender like in Spanish?
No,we dont use the preposition "a" in this case. Compreender is usually interchangeable but on my view compreender is meant "dig deeper", for example "entendi mas não compreendi", meaning you were able to understand, but not that much.... so, entender is general, compreender is usually related to a complete understanding of the things involved in.
why wont it let you use ela compreende o professor... it seems like that would be ok too?
I was pretty sure you could use "perceber" here. Or maybe it's a Portuguese from Portugal thing?