This is the 497th most frequent Norwegian word.
jakob
"Jakob" is a Norwegian male given name, equivalent to "Jacob" in English.
In this sentence, 'Jakob' is a proper noun referring to a person's name.
Jakob er en meget flink student.
Jacob is a very diligent student.
Here, 'Jakobs' is the possessive form of the proper noun 'Jakob', denoting ownership.
Jeg leste Jakobs bok i går.
I read Jacob's book yesterday.
In this usage, 'Jakob' continues to function as a proper noun serving as the subject of the sentence.