This is the 6846th most frequent Russian word.
ён
The Russian word "ён" does not exist; the correct word is "он," meaning "he" or "it" (for masculine nouns).
In this sentence, "он" is used as a pronoun to refer to a male person.
Он пришёл домой.
He came home.
Here, "он" functions as the subject of the sentence and represents the male individual who loves the action.
Он любит читать книги.
He loves reading books.
"Он" here is used as a pronoun to specify the person being referred to in the clause "he knows this."