Udvidelsen er ny.

In Danish, the definite article is often attached to the end of the noun instead of being a separate word.

• en udvidelse = an extension / an expansion
• udvidelsen = the extension / the expansion

So -en at the end means the here.

This is very common in Danish:

• en bog → bogen = the book
• en bil → bilen = the car

The base form is udvidelse.

That gives you:

• udvidelse = the noun stem
• en udvidelse = an extension / an expansion
• udvidelsen = the extension / the expansion

So the sentence uses the definite singular form.

Because udvidelse is an en-word (common gender noun), not an et-word (neuter noun).

The adjective new changes form depending on grammar:

• en noun, singular: ny
• et noun, singular: nyt
• plural / definite contexts: nye

So:

• en ny udvidelse = a new extension
• et nyt hus = a new house
• de nye huse = the new houses

Since udvidelsen is based on en udvidelse, the predicate adjective is ny.

You usually learn the noun together with its article:

• en udvidelse

That tells you its grammatical gender. In Danish, this matters because it affects:

• the definite ending
• adjective forms
• some pronouns

For this noun:

• indefinite: en udvidelse
• definite: udvidelsen
• adjective with it: ny

That is because ny here is a predicate adjective, not an adjective directly placed before the noun.

Compare:

1. Udvidelsen er ny.
   Here ny comes after er and describes the subject. Predicate adjectives usually do not take the definite -e ending just because the noun is definite.

2. Den nye udvidelse
   Here the adjective comes directly before the noun. In that position, Danish uses nye in a definite phrase.

So:

• Udvidelsen er ny. = predicate adjective
• Den nye udvidelse = attributive adjective before the noun

This is an important difference in Danish.

It follows the normal Danish statement pattern:

• Udvidelsen = subject
• er = verb
• ny = subject complement / predicate adjective

So literally the structure is:

The extension + is + new

This is the standard word order for a simple main clause.

Yes. Er is the present tense of at være = to be.

So:

• jeg er = I am
• du er = you are
• han/hun er = he/she is
• udvidelsen er = the extension is

In this sentence, it works just like English is.

Yes, but it does not mean exactly the same thing as the full sentence.

• Udvidelsen er ny. = The extension is new.
• Den nye udvidelse = the new extension

The first is a complete sentence.
The second is only a noun phrase, not a full sentence.

So if you want to make a statement, Udvidelsen er ny is correct.
If you just want to name or refer to something, den nye udvidelse is fine.

A rough guide is something like oo-VEE-thul-sen, but the real Danish pronunciation is less straightforward than English spelling suggests.

A few helpful points:

• u is not pronounced like English you
• d in Danish can be very soft
• the ending -elsen is usually reduced in natural speech
• stress is on the second syllable: ud-VI-del-sen

If you are learning pronunciation, it is best to listen to native audio, because Danish spelling and pronunciation often do not match in an obvious way for English speakers.

Not necessarily. It can mean several related things depending on context, such as:

• an extension
• an expansion
• an enlargement
• sometimes an extension period or added scope, depending on context

So the exact English translation depends on what is being talked about. Grammatically, though, the sentence works the same way.

No, not in standard Danish.

Nyt is used with et-words, but udvidelse is an en-word.

So the correct sentence is:

• Udvidelsen er ny.

Using nyt here would sound grammatically wrong.

The indefinite version would be:

• En udvidelse er ny.

That means An extension is new, though in real usage this is less natural unless the context makes it clear which extension you are talking about in a general way.

More commonly, you might see:

• En ny udvidelse = a new extension
• Udvidelsen er ny = the extension is new

Because Danish usually marks definiteness with a suffix on the noun.

English:

• the extension

Danish:

• udvidelsen

But Danish can also use a separate determiner in some cases, especially when an adjective comes before a definite noun:

• den nye udvidelse = the new extension

So Danish has two patterns:

• noun alone with definite ending: udvidelsen
• determiner + adjective + noun with definite marking: den nye udvidelse

That difference often feels unfamiliar to English speakers at first.