Learn Hardcore Norwegian: Kartet blir oppdatert hvert år fordi veiene endrer seg. - The map is updated every year because the roads change.

That is the periphrastic passive in Norwegian. Blir (the present tense of bli, “to become”) + the past participle oppdatert (from oppdatere, “to update”) together form the passive voice. So kartet blir oppdatert literally means “the map is being updated” or “the map gets updated.”

Could we say Kartet er oppdatert hvert år instead? Is there any nuance?

Yes, you could, but there’s a slight difference:

Kartet er oppdatert hvert år uses er (“is”) + past participle, which describes a state: “the map is updated every year” (it remains up-to-date).
Kartet blir oppdatert hvert år puts the focus on the action happening each year (“the map gets updated”). If you want to emphasize the annual updating process, blir is more natural.

What’s the difference between blir oppdatert and oppdateres?

Both express the passive, but in two styles:

Blir oppdatert is the periphrastic passive (using bli + past participle) and is very common in speech.
Oppdateres is the synthetic or -s passive (adding -s to the verb) and is more formal or written. Both translate as “is/gets updated.”

Why is kartet used instead of kart?

Kartet is the definite singular form of kart (“map”). In English we say “the map,” and Norwegian marks that with the suffix -et. If you said et kart, that would mean “a map.”

Why do we say hvert år instead of hver år?

In Norwegian år is a neuter noun. The distributive pronoun hver has three forms:

hver for masculine/feminine nouns (hver dag “each day”)
hvert for neuter nouns (hvert år “each year”)
hver(e) for plurals (hver uke – “every week,” but plural is less common here)

Why is seg added in endre seg? What does that achieve?

Endre by itself is transitive (“to change something”). Endre seg is the reflexive/intransitive form meaning “to change (on its own).” Here the roads change themselves, so you need seg to show the subject is undergoing the change.

In the clause fordi veiene endrer seg, why isn’t the verb at the end of the clause?

Unlike German, Norwegian subordinate clauses introduced by a conjunction (fordi, “because”) still follow V2 word order: the finite verb comes second. The conjunction doesn’t count as a clause element, so it goes: fordi (subordinator) + veiene (subject) + endrer (verb) + seg.

Why is veiene spelled with two es at the end?

Veien is “the road” (singular definite). The plural indefinite is veier (“roads”). To make that definite plural, Norwegian adds -ne to veier, giving veiene. The root ends in –e already, so you see two e’s in a row.

How do you pronounce oppdatert? Where is the stress and how do you handle the consonant cluster?

Stress is on the second syllable: opp-DA-ter(t). The initial ppd cluster is broken up by stress: [ɔpːˈdɑːtər], often simplified to [opˈdɑːtəʁt] in Eastern Norwegian. The final -t may be lightly pronounced or dropped in rapid speech, but the word remains clear.