Breakdown of Os amigos estão nos cafés.
o amigo
the friend (m)
estar
to be (temporary / location)
nos
in the / on the / at the (m.pl)
o café
the café
Questions & Answers about Os amigos estão nos cafés.
What exactly is nos made of?
nos is a combination of the preposition em (in, on, or at) and the masculine plural definite article os (the). Whenever you want to say "in the" before a masculine plural noun like cafés, you must combine em + os to make nos.
Why do we use estão instead of são here?
Why does the word cafés have an accent mark?
The accent mark tells you two things: first, that you should stress the final syllable when speaking, and second, that the "e" has an open sound, similar to the "e" in the English word "pet".
Could I leave out Os and just say Amigos estão nos cafés?
No. In Portuguese, when talking about specific people or things as the subject of a sentence, you generally must include the definite article (Os, meaning "the"). You cannot drop it like we sometimes do in English.