Learn Portuguese (Portugal): Quando é o nosso voo?

Quando means "when" and asks for a general time, day, or date. A que horas specifically means "at what time" (like 3:00 PM). You could ask A que horas é o nosso voo? if you only need the exact clock time, but quando is more flexible if you want to know the day or the general timeframe.

Why do we use é (from the verb ser) instead of está (from estar)?

In Portuguese, we use ser (to be) for events that happen or take place, like a flight, a meeting, or a party. Even though you might think of a flight schedule as temporary, the scheduled event itself is treated as a fixed occurrence, so we use ser.

Why is there an o before nosso?

In European Portuguese, you almost always put a definite article (o, a, os, as — meaning "the") before a possessive word like nosso (our). Because voo (flight) is a masculine singular word, we use the masculine singular article o. Literally, the sentence is "When is the our flight?".

Why does voo have two 'o's, and how do I pronounce it?

The double 'o' is just how this noun is spelled, coming from the verb voar (to fly). To say it, you pronounce a slightly elongated 'o' sound, sounding a bit like "voh-oh".