Bist du müde?
English: Are you tired?
Yes/No questions (Ja/Nein-Fragen) in German are questions that can be answered with 'yes' or 'no'. The verb comes at the beginning of the sentence.
Use this structure when you want to ask a question that can be answered with 'yes' or 'no' in German.
Bist du müde?
English: Are you tired?
Hast du Geschwister?
English: Do you have siblings?
Wohnst du in Hamburg?
English: Do you live in Hamburg?
Spricht er Englisch?
English: Does he speak English?
Kommt ihr heute?
English: Are you (all) coming today?