This is the 200th most frequent Dutch word.
zijn
"Zijn" means "to be."
Here, "zijn" is a possessive pronoun, meaning "his," showing possession or relation.
Zijn ouders wonen in Amsterdam.
His parents live in Amsterdam.
Here, "ben" is a conjugation of the verb "zijn" in the first person singular, used as a linking verb to describe a state of being.
Ik ben gelukkig vandaag.
I am happy today.
Here, "is" is a conjugation of the verb "zijn" in the third person singular, used to indicate location or existence.