This is the 5th most frequent Persian word.
است
"است" means "is" in English, used as the third-person singular form of the verb "to be."
Demonstrates 'است' as a linking verb to describe identity.
این یک کتاب است.
This is a book.
Shows 'است' as part of a compound verb structure to indicate present continuous tense.
او در حال خواندن کتاب است.
She is reading a book.
Uses 'است' to describe the state or quality of something.