Learn Portuguese (Portugal): Onde está o médico na quinta-feira?

In Portuguese, you use the preposition em (in/on) to say something happens on a certain day of the week. The days from Monday to Friday all end in -feira and are feminine words. Because it's feminine, em combines with the word for "the" (a) to become na.

How do the numbers work for the days of the week? Why is Thursday quinta-feira?

The Portuguese workweek starts counting on Monday, which is the "second day" (segunda-feira). Following that pattern, Tuesday is the third (terça-feira), Wednesday is the fourth (quarta-feira), and Thursday is the fifth (quinta-feira).

Why do we use está instead of é for the word "is"?

We use the verb estar (which becomes está for he/she/it) when talking about someone's physical location. Even though a doctor's schedule might be a fixed routine, you always use estar rather than ser to say where someone or something is.

If the doctor was a woman, how would this sentence change?