Learn Portuguese (Portugal): De onde é o professor?

In Portuguese, prepositions like de (from) must stay attached to their question word, which is onde (where) in this case. You can never end a sentence with a preposition like you often do in English. So, 'Where is the teacher from?' is literally built as 'From where is the teacher?' (De onde é o professor?).

Why do we use é here instead of está?

We use é, which comes from the verb ser (to be), for permanent traits like someone's origin or nationality. Since where the teacher is from does not change, we use é. If you wanted to ask where the teacher is physically standing right now, you would drop the De and use the temporary verb estar: Onde está o professor?.

Why is the word order é o professor instead of o professor é?

In Portuguese, when a question begins with a question word like De onde (from where) or Quem (who), the verb usually comes right after that question word. The subject (o professor) then follows the verb.

How would I ask this if the teacher is female?

You would change the masculine word o professor to the feminine version, making the sentence De onde é a professora?.