"Yes or no" questions are the simplest, because all you have to do is add a question mark to the end. For example, Tu estás em Portugal. (You are in Portugal.) becomes Tu estás em Portugal? (Are you in Portugal?) The question mark changes the intonation of the sentence and transforms it into a question.
In English, you could reply simply by saying “yes” or “no”, but in Portuguese, saying just sim or não sounds a bit too abrupt or incomplete. Instead, you should use the same verb from the question in your reply. For example, to reply “yes” to Tu estás em Portugal?, you could say: Estou (I am), Sim, estou (Yes, I am), or even Estou sim (Yes, I am). To reply “no”, you could say Não estou or Não, não estou.
Another way to form a Portuguese question is to add a phrase like não é? to the end of a statement. For example: Ela é portuguesa, não é? (She is Portuguese, isn’t she?, She is Portuguese, right?) This type of question is used when you’re almost sure of what you’re saying, or even as a rhetorical question. Não é is the most common phrase, but it also works with other verbs. For example: Ela está em casa, não está? (She's at home, isn’t she?). Just as before, you use the verb in your reply: Está (She is) / Não está (She’s not), Sim, está (Yes, she is) / Não, não está (No, she’s not), or Está sim (Yes, she is).
To hear the pronunciation and learn more about Portuguese questions, visit us at www.PracticePortuguese.com/AnswerKey