The Genitive case (Tamlayan Hali / İlgi Hali) is used to show possession or a relationship between two nouns. It typically translates to "of" or the English possessive 's (apostrophe s). The noun in the genitive case is the "possessor."

The genitive case marks the first noun in a two-part noun phrase construction called "isim tamlaması" (noun compound), where the second noun (the "possessed") takes a possessive suffix.

Suffixes:

The genitive suffix follows I-Type vowel harmony:

• If the last vowel of the noun is a or ı, add -ın.
• If the last vowel of the noun is e or i, add -in.
• If the last vowel of the noun is o or u, add -un.
• If the last vowel of the noun is ö or ü, add -ün.

If the noun ends in a vowel, the buffer consonant 'n' is inserted before the suffix (e.g., -nın, -nin, -nun, -nün).

Examples (showing the genitive noun only):

• evin... (of the house... / the house's...) (ev + -in)
• okulun... (of the school... / the school's...) (okul + -un)
• Ali'nin... (of Ali... / Ali's...) (Ali + -nin)
• arabanın... (of the car... / the car's...) (araba + -nın)
• kapının... (of the door... / the door's...) (kapı + -nın)
• gözlüğün... (of the glasses... / the glasses'...) (gözlük + -ün, k→ğ)

Note: The genitive case almost always appears with a second noun that takes a possessive suffix. For full possessive phrases, see "Compound Nouns (İsim Tamlamaları)" and "Possessive Suffixes."
Example of full phrase: evin kapısı (the house's door).