Questions in Turkish can be formed in several ways, primarily using the question particle mi/mı/mu/mü or interrogative words (pronouns, adjectives, adverbs).

1. Yes/No Questions with mi/mı/mu/mü:

This particle is added after the word being questioned. If questioning the verb, it follows the verb (without personal suffixes), and then personal suffixes are attached to the particle.

• Geldin mi? (Did you come?) (geldi + n + mi → geldin mi? or more commonly geldi mi + sin? → geldin mi?. Actually: geldi (he/she/it came) + mi? + sin (you) → O geldi mi? Sen geldin mi?. Let's rephrase: Sen geldin mi? is correct. The structure for verb questioning is: Verb (full conjugation without personal suffix if the suffix moves to 'mi') + mi + personal suffix)
• Çay istiyor musun? (Do you want tea?)
• Bu kitap mı? (Is this a book?) (Questioning the noun)
• Güzel mi? (Is it beautiful?) (Questioning the adjective)

2. Questions with Interrogative Words:

Interrogative words (who, what, where, when, why, how, which, etc.) are placed in the sentence where the answer would normally appear. The question particle mi is generally NOT used with these words.

• Kim (Who?): Kim geldi? (Who came?)
• Ne (What?): Ne yapıyorsun? (What are you doing?)
• Nerede (Where?): Nerede oturuyorsun? (Where do you live?)
• Ne zaman (When?): Ne zaman döneceksin? (When will you return?)
• Nasıl (How?): Nasıl gidiyor? (How is it going?)
• Neden/Niçin (Why?): Neden üzgünsün? (Why are you sad?)
• Hangi (Which?): Hangi kitabı okudun? (Which book did you read?)
• Kaç (How many?): Kaç kardeşin var? (How many siblings do you have?)

Intonation:

For yes/no questions, there's typically a rising intonation at the end of the sentence, especially on the question particle. For questions with interrogative words, the intonation may fall at the end.