Mobilabonnementet er forudbetalt.

Because Danish usually writes compound nouns as a single word.

So:

• mobil
  • abonnement → mobilabonnement
• mobilabonnementet = the definite form of that compound

This is very common in Danish. Where English often uses two words, Danish often uses one:

• mobile subscription → mobilabonnement
• train station → togstation
• coffee cup → kaffekop

The last part of the compound is the main noun, and the first part modifies it.

The base form is et mobilabonnement.

That means:

• indefinite singular: et mobilabonnement
• definite singular: mobilabonnementet

The ending -et is the definite article attached to the noun, so Danish often expresses the at the end of the word instead of with a separate word before it.

Because abonnement is a neuter noun in Danish.

Danish nouns have grammatical gender, and the singular definite ending depends on the gender:

• common gender: often -en
• neuter: often -et

Since the head noun is abonnement, and it is et abonnement, the definite form becomes abonnementet. The same applies to the compound:

• et mobilabonnement
• mobilabonnementet

In Danish, the definite article is often attached to the end of the noun.

So instead of a separate word like English the, Danish often uses a suffix:

• abonnement = subscription
• abonnementet = the subscription

That is why Mobilabonnementet already includes the idea of the mobile subscription.

A separate definite word such as det is used in some other structures, especially when an adjective comes before the noun:

• mobilabonnementet = the mobile subscription
• det forudbetalte mobilabonnement = the prepaid mobile subscription

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

So:

• jeg er = I am
• du er = you are
• det er = it is

In this sentence, er links the subject Mobilabonnementet to the description forudbetalt. It works just like English is in is prepaid.

Here, forudbetalt functions like an adjective, describing the state of the subscription.

It is closely related to a past participle and comes from the idea of paying in advance:

• forud = in advance / beforehand
• betalt = paid

So grammatically, you can think of it as a participle being used adjectivally: it describes a condition or status.

That is very common in Danish, just as in English:

• Døren er lukket = The door is closed
• Regningen er betalt = The bill is paid
• Mobilabonnementet er forudbetalt = The mobile subscription is prepaid

Because after er with a singular subject, forudbetalt is the normal form here.

Compare:

• Mobilabonnementet er forudbetalt = singular, predicate after er
• det forudbetalte mobilabonnement = definite noun with adjective before it
• de forudbetalte abonnementer = plural

So forudbetalte is commonly used when the adjective stands before a definite noun or with plural nouns, but forudbetalt is the normal form in this sentence.

Yes.

You can say:

• et forudbetalt mobilabonnement = a prepaid mobile subscription
• det forudbetalte mobilabonnement = the prepaid mobile subscription

This is useful because it shows an important Danish pattern:

• when the adjective comes before a definite noun, Danish usually uses a separate definite article too: det
• the adjective often takes -e in that structure: forudbetalte

So:

• Mobilabonnementet er forudbetalt
• det forudbetalte mobilabonnement

Both are correct, but the grammar is slightly different.

Because mobilabonnement is the normal Danish compound for a mobile-phone plan/subscription.

Mobilt abonnement would sound more literal, like a subscription that is mobile, which is not the usual idiomatic way to say it.

Danish often prefers a compound noun where English might use a noun + adjective phrase. So mobilabonnement is the standard word you should learn.

Here are the most useful versions:

• indefinite: Et mobilabonnement er forudbetalt.
• negative: Mobilabonnementet er ikke forudbetalt.
• question: Er mobilabonnementet forudbetalt?

This is a good pattern to remember:

• statement: subject + verb + complement
• yes/no question: verb + subject + complement
• negation: ikke usually comes after the finite verb

Yes.

This sentence has standard main-clause word order:

• Mobilabonnementet = subject
• er = finite verb
• forudbetalt = complement

So the pattern is:

• Subject + Verb + Complement

Danish also follows the verb-second rule in main clauses. That means if something else comes first, the verb still stays in second position:

• Normalt er mobilabonnementet forudbetalt.
• I Danmark er mobilabonnementet forudbetalt.

That is a very important rule in Danish sentence structure.

Yes, it is natural and correct.

It sounds like something you might see:

• on a website
• in customer information
• in a contract
• in telecom/payment settings

It is slightly formal or informational in tone, which fits the topic well. In a more conversational context, a Dane might also say something like:

• Du betaler abonnementet forud = You pay the subscription in advance

But Mobilabonnementet er forudbetalt is perfectly normal Danish.