Der findes mange mobilabonnementer.

In Der findes mange mobilabonnementer, der is a dummy subject used in existential sentences — the same kind of there as in English There are many mobile plans.

It does not mean there as a place.

So here:

• der = existential there
• findes = exist / are to be found
• mange mobilabonnementer = many mobile subscriptions/plans

This structure is very common in Danish when you want to say that something exists or is available.

Here, findes means something like:

• exist
• are available
• can be found

So Der findes mange mobilabonnementer means that many mobile subscriptions/plans exist or are available.

A useful thing to know is that findes comes from the verb finde (to find), but in this kind of sentence it works more like exist than like literal be found.

They are very similar, but not always identical in tone.

• Der er mange mobilabonnementer = There are many mobile subscriptions/plans
• Der findes mange mobilabonnementer = There exist / there are many mobile subscriptions/plans

In practice:

• der er is more common in everyday speech
• der findes can sound a bit more formal, written, or descriptive
• der findes often puts a little more emphasis on existence or availability

So yes, both can work, but der findes is slightly more specific in style.

Because in Danish, just like in English, you do not use an article before a plural noun when you mean many + plural noun.

So:

• mange mobilabonnementer = many mobile subscriptions
• not mange de mobilabonnementer in this sentence

You would only use a definite form if you meant the mobile subscriptions, for example in a different context.

Because Danish, like English, often makes compound nouns, but Danish usually writes them as one word.

So:

• mobil = mobile / cell phone
• abonnement = subscription
• mobilabonnement = mobile subscription / phone plan
• mobilabonnementer = mobile subscriptions / phone plans

English often writes similar ideas as separate words, but Danish usually joins them together.

Because -er is a very common plural ending in Danish.

Here the pattern is:

• et mobilabonnement = a mobile subscription
• mobilabonnementer = mobile subscriptions

This is a regular neuter noun pattern for many words, though not all Danish nouns form the plural in the same way.

Because Danish verbs do not change according to the subject in the present tense.

So Danish uses the same present-tense verb form with:

• jeg
• du
• han/hun
• vi
• de

For example:

• der findes ét abonnement
• der findes mange abonnementer

The verb stays findes in both cases.

This is easier than English in one way, because you do not need to learn separate forms like is/are.

Mange means many and modifies the plural noun mobilabonnementer.

So:

• mange = many
• mange mobilabonnementer = many mobile subscriptions

It tells you that the number is large, but it does not specify an exact amount.

Grammatically, that translation is possible in a very literal sense, but it is not the most natural English translation.

The most natural translations are:

• There are many mobile subscriptions
• There exist many mobile subscriptions
• Many mobile subscriptions are available

So when learning the Danish sentence, it is better to understand findes here as exist / are available, not as a word-for-word passive of find.

Yes, it is natural, but it may sound a bit more formal or informational than the simpler Der er mange mobilabonnementer.

You might see Der findes ... especially in:

• advertisements
• websites
• descriptions
• informative writing

In everyday conversation, many speakers would often prefer der er unless they want to stress existence or availability.