Nøkkelen er borte.

to be

Breakdown of Nøkkelen er borte.

• nøkkelen: the key
• borte: gone

Questions & Answers about Nøkkelen er borte.

What is the word nøkkelen, and why doesn’t it use a separate article like “the key”?

Nøkkelen is the definite singular form of nøkkel (key). In Norwegian, the definite article is suffixed to the noun instead of placed before it.

• indefinite singular = nøkkel (a key)
• definite singular = nøkkelen (the key)

What does borte mean, and why is it not inflected?

Borte means “gone” or “away.” Here it’s used predicatively after er (“is”). Predicative adjectives (and words like borte) are not inflected for gender, number or definiteness in Norwegian.
Compare:

• Han er syk (“He is sick”)
• De er syke (“They are sick”)
• Nøkkelen er borte (“The key is gone”)

How would I make this a question to ask “Is the key gone?”

Norwegian inverts the subject and verb for yes/no questions (V2 rule):
Er nøkkelen borte?

What are the plural forms of nøkkel?

• Indefinite plural: nøkler (keys)
• Definite plural: nøklene (the keys)