Turkish Question Particle: mı, mi, mu, mü

A yes/no question needs no new word order and no new verb. You add one small word after the statement: Bu araba. → Bu araba mı? The little word is mı, mi, mu or mü, and it is always written separately.

Which of the four you write follows four-way harmony with the last vowel of the word before it: araba mı, ev mi, okul mu, Türk mü.

The particle follows the word you are asking about. Usually that is the last word of the sentence, but Kitap mı okuyorsun? asks whether it is a book you are reading. With I, you and we the personal ending moves onto the particle: Öğrenci misin? Yorgun musunuz?