Learn Turkish: Doktorun adı ne? - What is the doctor's name?

This is the genitive suffix, which is the focus of this lesson! It works just like the English "'s". Adding -un changes "doctor" to "doctor's" (or "of the doctor").

Why is the suffix exactly -un instead of -in or -nın?

The genitive suffix follows 4-way vowel harmony. Since the last vowel in doktor is 'o', the suffix needs a 'u'. Also, because doktor ends in a consonant (r), we don't need a buffer letter 'n' at the start of the suffix. Therefore, it becomes -un.

Why is there an -ı at the end of ad (name)?

In Turkish, it is not enough to just add "'s" to the owner; you must also attach a possessive suffix to the thing being owned. The -ı is the 3rd person possessive suffix meaning "his/her/its". So, doktorun adı literally translates to "the doctor's his-name".

Where is the word for "is" in this sentence?

In simple present tense sentences, Turkish often drops the equivalent of the verb "is". You simply state the subject (doktorun adı, the doctor's name) and the question word (ne, what) right next to each other.