Under omleveringen bruger kunden låneapparatet.

Here under means during.

So Under omleveringen = during the replacement / exchange process.

This is a very common Danish use of under with time periods or processes:

• under mødet = during the meeting
• under reparationen = during the repair
• under opholdet = during the stay

It does not mean physical under in this sentence.

Omleveringen is the definite form of omlevering.

• omlevering = replacement delivery, exchange, re-supply, re-delivery
• omleveringen = the replacement delivery / the exchange process

It is a noun built from:

• om- = again / re-
• levering = delivery

In context, it usually refers to the process where a product is being replaced.

Because Danish often uses the definite form where English would also say the.

• omlevering = a replacement / replacement in general
• omleveringen = the specific replacement being talked about

In this sentence, it is a specific event or process, so the definite form is natural:

• Under omleveringen = during the replacement

The definite article is attached to the noun as an ending:

• en omlevering
• omleveringen

Kunden means the customer.

Again, Danish usually adds the definite article as a suffix:

• en kunde = a customer
• kunden = the customer

The sentence is talking about a specific customer, not just any customer:

• bruger kunden = the customer uses

So the structure is:

• kunden = subject
• bruger = verb
• låneapparatet = object

Låneapparatet means the loan device, the temporary replacement device, or the device on loan.

It is a compound noun:

• låne- = loan-, borrowed-, temporary
• apparat = device, apparatus, machine
• låneapparatet = the loan device

This kind of compound is very common in Danish. English often uses several separate words where Danish uses one compound.

Depending on context, it could refer to something like:

• a loan phone
• a temporary hearing aid
• a replacement machine
• a device the customer can use while waiting

Because Danish forms compound nouns very freely.

So instead of writing something like loan device as two words, Danish normally combines them:

• låne
  • apparat → låneapparat
• definite form: låneapparatet

This is one of the most important habits to get used to in Danish. If two words belong closely together as one concept, Danish will often make them a single word.

Bruger is the present tense of at bruge = to use.

Forms:

• at bruge = to use
• bruger = use / uses
• brugte = used
• har brugt = have/has used

In this sentence:

• kunden bruger låneapparatet = the customer uses the loan device

Danish present tense is often used in instructions, policies, and general statements, just like English:

• Kunden bruger låneapparatet = The customer uses the loan device

Because Danish follows the V2 rule in main clauses: the finite verb usually comes in the second position.

The first position can be filled by different elements. Here, the sentence starts with a time phrase:

• Under omleveringen = first position

Then the finite verb must come next:

• bruger

Then comes the subject:

• kunden

So:

• Under omleveringen bruger kunden låneapparatet.

If you start with the subject instead, you get:

• Kunden bruger låneapparatet under omleveringen.

Both are grammatical, but the emphasis is slightly different:

• starting with Under omleveringen emphasizes the time frame
• starting with Kunden emphasizes the customer

Yes, absolutely.

That version is also correct:

• Kunden bruger låneapparatet under omleveringen.

The meaning is the same. The difference is mainly emphasis and style.

Compare:

• Under omleveringen bruger kunden låneapparatet.
  Focuses first on when
• Kunden bruger låneapparatet under omleveringen.
  Focuses first on who

Danish is flexible in this way, but the verb still follows the normal main-clause pattern.

Apparat is a normal Danish word, but it can sound a bit formal or technical depending on context.

It often means:

• device
• apparatus
• machine
• piece of equipment

In everyday modern language, other words may also be common depending on the object:

• telefon = phone
• enhed = unit/device
• maskine = machine

So låneapparatet is understandable, but the exact nuance depends on the field. In medical, technical, or service contexts, it can sound very natural.

A rough English-friendly guide could be:

UN-ner OM-leh-vair-ing-en BROO-er KUN-den LOAN-eh-ah-pa-rad-ed

A few useful notes:

• d in under is usually soft, so it may sound a bit like unner
• bruger is often pronounced more like broo-er
• -et at the end of låneapparatet is unstressed
• Danish pronunciation is often much softer and more reduced than the spelling suggests

If you want to sound more natural, focus especially on not pronouncing every consonant too strongly.

It can be understood as either, depending on context, but most likely it sounds like a general instruction, policy, or standard procedure.

For example:

• while the product is being replaced, the customer uses the loan device

So even though bruger is present tense, it may describe:

• a routine
• a service process
• a company policy
• a standard arrangement

This is very common in Danish and English alike.