Kirken er gammel.

Because kirken is the definite singular form: the church.

In Norwegian, the definite article is usually attached to the end of the noun instead of being a separate word before it.

• kirke = church
• kirken = the church

So the -en ending here works like English the.

For many nouns in Bokmål, -en is the definite singular ending used with masculine-style forms.

With kirke, this is especially interesting because the noun can often be treated as either feminine or masculine in Bokmål:

• en kirke – kirken
• ei kirke – kirka

Both are possible in Bokmål. Your sentence uses the common form kirken.

Yes. In Bokmål, kirka er gammel is also correct if you are using feminine forms.

So these are both acceptable:

• Kirken er gammel
• Kirka er gammel

The version with kirken is often taught early because many learners first meet the masculine/common-gender pattern.

Because adjectives in Norwegian change form depending on gender, number, and sometimes whether they are used before or after the noun.

Here, gammel matches a singular non-neuter noun.

Compare:

• en gammel bil = an old car
• ei gammel kirke = an old church
• et gammelt hus = an old house
• gamle hus = old houses

In Kirken er gammel, the adjective comes after er, so it is a predicative adjective, and the correct form here is gammel.

Because Norwegian usually puts definiteness on the noun itself.

So instead of saying something like the church, Norwegian often says church-the, which becomes kirken.

However, when there is an adjective directly before a definite noun, Norwegian usually uses double definiteness:

• kirken = the church
• den gamle kirken = the old church

So with just the noun, the ending is enough. With an adjective before the noun, you normally add both den and the definite noun ending.

Because er means is, and after forms of to be, Norwegian often uses an adjective to describe the subject.

So the structure is:

• Kirken = subject
• er = verb
• gammel = description of the subject

This is the same basic idea as in English:

• The church is old

If you put the adjective before the noun instead, the structure changes:

• den gamle kirken = the old church

This sentence has the normal basic word order for a statement:

• subject + verb + complement
• Kirken + er + gammel

That said, Norwegian main clauses follow the V2 rule, which means the finite verb usually comes in the second position. In a simple sentence like this, that gives the same order English learners expect.

For example:

• Kirken er gammel
• I dag er kirken gammel

In both sentences, the verb er stays in second position.

These are useful patterns to compare.

If the adjective comes before the noun in a definite phrase, you normally use double definiteness:

• Den gamle kirken = the old church

So:

• Den gamle kirken er gammel = The old church is old

If you add another adjective after er, you can coordinate them just like in English:

• Kirken er gammel og vakker = The church is old and beautiful

Notice that adjectives after er describe the subject and are not preceded by den.

A simple learner-friendly approximation is:

KIR-ken er GAM-mel

A few pronunciation notes:

• kirken has two syllables: kir-ken
• er is usually short
• gammel has two syllables: gam-mel

Depending on dialect, the r sound can vary, and the first sound in kirken may sound softer than an English k to some learners. But if you say it clearly as KIR-ken er GAM-mel, you will be understood well.