This is the 7501st most frequent Swedish word.
steven
"Steven" is not a Swedish word; it is a name.
In this sentence, "Steven" is a proper noun referring to a person.
Steven köpte en ny bok igår.
Steven bought a new book yesterday.
Here, "Stevens" is the possessive form indicating that the turn to speak belongs to Steven.
Det var Stevens tur att prata.
It was Steven's turn to speak.
The word "Steven" acts as the subject of the sentence, representing the person named Steven.