Learn Turkish: Evin çatısı çok büyük. - The roof of the house is very big.

The word ev means "house". Because this lesson focuses on the genitive case (which acts like "of" or "'s" in English), we add the suffix -in to make it evin, meaning "the house's" or "of the house".

What does the -sı at the end of çatısı do?

In Turkish, when one thing belongs to another, both words get a suffix. Since evin has the "owner" suffix, the owned object (çatı, meaning "roof") needs a possessive suffix. The -sı acts like "its", so evin çatısı literally means "the house's its-roof".

Why does çatı take -sı instead of just -ı?

The word çatı ends in a vowel. If we just added the third-person possessive suffix -ı, we would have two vowels right next to each other (çatıı). To prevent this, Turkish uses the buffer consonant s, making the suffix -sı.

There is no word for "is" in the Turkish sentence. How do we know it means "is very big"?

In Turkish, there is no separate word for "is" or "are" that you need to use with adjectives in basic descriptive sentences. Simply placing çok büyük (very big) after the subject evin çatısı (the roof of the house) forms the complete sentence.