This is the 6977th most frequent Swedish word.
pojkens
"Of the boy" or "the boy's" (possessive form of "pojken").
In this sentence, 'pojkens' is used as a possessive noun to indicate that the bicycle belongs to the boy.
Pojkens cykel är röd.
The boy's bicycle is red.
Here, 'pojkens' again acts as a possessive noun, showing possession of the book by the boy.
Vi såg pojkens bok på bordet.
We saw the boy's book on the table.
In this context, 'pojkens' signifies possession, indicating that the parents being referred to are those of the boy.