Energimærket er på elapparatet.

Because Danish usually adds the definite article to the end of the noun instead of putting a separate word like the in front.

• et energimærke = an energy label
• energimærket = the energy label

And:

• et elapparat = an electrical appliance
• elapparatet = the electrical appliance

The ending -et is the common definite singular ending for many neuter nouns.

You usually have to learn the gender with the noun.

Here, the basic forms are:

• et energimærke
• et elapparat

That tells you they are neuter nouns. In Danish, noun gender is not always predictable, so it is best to memorize nouns together with en or et.

Because Danish normally uses a suffixed definite article.

In English, you say:

• the energy label
• the electrical appliance

In Danish, that becomes:

• energimærket
• elapparatet

So Danish often expresses the by changing the noun itself, rather than adding a separate word before it.

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 simply means is.

På usually means on.

In this sentence, it shows location: the label is on the appliance, probably attached to its surface.

This is a very natural choice in Danish for something physically placed or stuck onto an object.

A useful contrast:

• på = on
• i = in
• under = under

So på elapparatet means on the electrical appliance, not in it.

Yes. Danish very often forms compound nouns as one word.

So:

• el = electric / electrical
• apparat = appliance / device

Together:

• elapparat = electrical appliance

This is very normal in Danish. English often uses two words where Danish prefers one compound word.

El- is a common Danish element meaning electrical or related to electricity.

For example:

• elbil = electric car
• elregning = electricity bill
• elapparat = electrical appliance

So here it refers to a device that runs on electricity.

The basic order is:

subject + verb + adverbial/prepositional phrase

So here:

• Energimærket = subject
• er = verb
• på elapparatet = location phrase

This is very similar to English:

• The energy label
  • is
    • on the appliance

Yes, Danish can move the location phrase to the front for emphasis:

• På elapparatet er energimærket.

That is grammatical, but it sounds more marked or literary in many contexts. The neutral, everyday version is:

• Energimærket er på elapparatet.

A useful thing to notice: if something else comes first in a Danish main clause, the verb still stays in second position.

A rough English-friendly guide would be something like:

en-er-gee-MAIR-ket

A few useful points:

• gi in energi sounds like gee
• æ is a front vowel, somewhat like the a in cat, but not exactly
• the stress is mainly on mær

So the second part, mærket, is roughly MAIR-ket.

A rough guide is:

el-ap-pa-RAH-det

Useful points:

• stress falls mainly on ra
• the final -et is often pronounced more lightly than an English et
• Danish d in unstressed endings can sound softer than English learners expect

You do not need perfect pronunciation right away, but it helps to hear native audio because Danish vowel quality and reduced endings are important.

The indefinite singular forms are:

• et energimærke
• et elapparat

So if you wanted to say an energy label is on an electrical appliance, you would use those indefinite forms instead of the definite ones.

The common plural forms are:

• energimærke / energimærker / energimærkerne
• elapparat / elapparater / elapparaterne

So:

• singular indefinite: et energimærke
• singular definite: energimærket
• plural indefinite: energimærker
• plural definite: energimærkerne

And similarly for elapparat.

Because det is not the normal way to make a simple noun definite in Danish.

You usually say:

• energimærket = the energy label

not:

• det energimærke

The form det energimærke can exist, but it means something more like that energy label or is used in special structures. For a normal definite noun, Danish usually just adds the ending to the noun.

Yes, it is a natural and straightforward sentence.

It is short, clear, and uses standard Danish grammar:

• definite nouns with -et
• present tense er
• location with på

So it is a good example of basic Danish sentence structure.