This is the 617th most frequent Norwegian word.
de
"They" or "you" (formal/plural).
Here, 'de' is used as a plural personal pronoun, equivalent to 'they' in English.
De er hjemme i dag.
They are at home today.
In this sentence, 'de' functions as a definite plural article adjectivally preceding a noun, 'nye bilene' (the new cars).
Ser du de nye bilene i gata?
Do you see the new cars on the street?
Here, 'de' functions as a demonstrative pronoun meaning 'those', referring to a specific group of people.