Learn Turkish: Uçağın motoru çok büyük. - The airplane's engine is very big.

Turkish uses a definite noun compound (Genitive + Possessive) to show exact ownership. You add a genitive suffix to the owner (uçağın = the airplane's) and a possessive suffix to the thing owned (motoru = its engine). Together, uçağın motoru literally acts like "the airplane's its engine".

Why does the word for airplane, uçak, change to uçağın with a ğ?

This happens because of consonant mutation. When you add a suffix that starts with a vowel—like the genitive suffix -ın—to a word ending in k, the k softens into a ğ (soft g). So, uçak + ın becomes uçağın.

Why is the suffix on motor exactly -u?

The word motor needs the 3rd-person possessive suffix (meaning "its"). Since motor ends in a consonant, we don't need the buffer letter s (which is only used if the word ends in a vowel). Because the last vowel in motor is o, 4-way vowel harmony tells us the suffix must be -u, making it motoru.

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