This is the 3rd most frequent Norwegian word.
som
"Som" in Norwegian means "as," "that," "who," or "which," depending on context.
In this case, 'som' functions as a relative pronoun to specify the type of teachers the speaker likes.
Jeg liker lærere som forklarer ting klart.
I like teachers who explain things clearly.
Here, 'som' is used to express resemblance or comparison, meaning 'as' indicating the speaker's role as a teacher.
Som lærer må jeg alltid forberede meg godt.
As a teacher, I always need to prepare thoroughly.
Here, 'som' is used as a relative pronoun introducing a relative clause that provides additional information about 'Denne mannen' (this man).