Learn Turkish: Kimya öğretmeni laboratuvarda çalışır mı? - Does the chemistry teacher work in the laboratory?

The aorist tense is used for general facts, routines, and habits. By asking çalışır mı?, you are asking about the teacher's general routine or job description ("Does the teacher work in the lab in general?"). If you used çalışıyor mu, it would specifically mean "Is the teacher working in the lab right now?".

How do we know to use the -ır suffix for the aorist form of çalışmak?

For verbs ending in a consonant, the aorist suffix depends on the number of syllables. One-syllable verbs usually take -ar or -er. Verbs with more than one syllable, like çalışmak (ça-lış), take -ır, -ir, -ur, or -ür. Following four-way vowel harmony for the last vowel ı, the suffix becomes -ır.

Why is the question particle mı used instead of mi or mu?

The question particle always follows four-way vowel harmony based on the word right before it. The preceding word is çalışır, which has the vowel ı in its final syllable. Therefore, the question particle must be mı, and as always, it is written as a separate word.

Why is there an -i at the end of öğretmeni?