ülkesinin
ülkesinin is a Turkish possessive suffix. It is formed by combining the noun "ülke" meaning "country" or "nation" with the possessive suffix "-si" which indicates third-person singular possession. Therefore, "ülkesinin" translates to "of his country," "of her country," or "of its country." This suffix is used to show that something belongs to or is related to a person's, animal's, or entity's country. For example, in the sentence "O, ülkesinin geleceği için çalışıyor" (He is working for the future of his country), "ülkesinin" clearly denotes that the future belongs to his country. The suffix "-nin" is a genitive case marker, indicating possession. The final "i" in "ülkesinin" is a buffer vowel that appears when the noun ends in a vowel and the possessive suffix begins with a vowel. This grammatical construction is common in Turkish to indicate belonging or origin in relation to a country. It is a fundamental part of Turkish grammar for expressing ownership or association with one's nation.