Vær opmærksom på datoen, før du sender ansøgningen.

Vær is the imperative form of at være (to be). Danish uses the imperative to give instructions, advice, warnings, or commands.

So Vær opmærksom på datoen means something like:

• Be aware of the date
• Pay attention to the date

This kind of imperative is very common in instructions and formal guidance.

Because opmærksom på is a fixed expression in Danish meaning:

• aware of
• attentive to
• paying attention to

The preposition på is required here.

Examples:

• Jeg er opmærksom på problemet. = I am aware of the problem.
• Vær opmærksom på reglerne. = Be aware of the rules.

So in your sentence, på datoen means to the date / of the date, depending on how you naturally translate it into English.

Datoen is the definite singular form of dato.

• en dato = a date
• datoen = the date

Danish usually adds the definite article to the end of the noun:

• en bog → bogen
• en ansøgning → ansøgningen
• en dato → datoen

Here, datoen means a specific date, probably one already known from context, such as a deadline or the date on a form.

Danish often uses a full clause after før (before):

• før du sender ansøgningen = before you send the application

This is very normal and natural. English can also do this:

• before you send the application

In some English contexts, you might also say:

• before sending the application

But Danish does not use that exact structure as freely here. The clause with du sender is the standard choice.

Because sender is a present tense form, not an infinitive.

• at sende = to send
• sender = send / are sending

In the clause før du sender ansøgningen, the subject is du (you), so Danish needs a finite verb:

• du sender = you send

If it were infinitive, it would need a different structure.

Ansøgningen is the definite singular form of ansøgning (application).

• en ansøgning = an application
• ansøgningen = the application

Just like datoen, the definite ending is attached to the noun.

This sentence refers to a specific application, not just any application.

Usually, ansøgning means application, especially in formal contexts such as:

• job application
• application for admission
• application for a permit
• application form in some contexts

Very often, ansøgning suggests a written request or formal submission.

For example:

• en jobansøgning = a job application
• at sende en ansøgning = to send an application

So in your sentence, ansøgningen is most likely a formal application of some kind.

The word order is the normal Danish order for a subordinate clause introduced by før:

• før = conjunction
• du = subject
• sender = verb
• ansøgningen = object

So:

før + subject + verb + object

This is very common in Danish subordinate clauses.

Examples:

• før du går = before you go
• før han kommer = before he comes
• før vi betaler regningen = before we pay the bill

In standard Danish punctuation, a comma is often placed before a subordinate clause, especially in traditional comma styles.

So in:

Vær opmærksom på datoen, før du sender ansøgningen.

the comma separates the main clause from the subordinate clause.

You will see this type of comma very often in written Danish.

It is neutral to fairly formal, and very common in written instructions, notices, and advice.

It sounds natural in contexts like:

• websites
• official letters
• forms
• instruction manuals
• customer information

In everyday speech, people might also say other things depending on tone, such as:

• Husk at tjekke datoen = Remember to check the date
• Se lige på datoen først = Just check the date first

But Vær opmærksom på datoen is perfectly natural and especially suitable in formal or instructional language.

Yes, very possibly.

Literally, datoen means the date, but in context it may refer to:

• the deadline
• the date written on the document
• the submission date
• the relevant calendar date

Danish often leaves this kind of detail to context, just like English sometimes does.

So even if the sentence literally says Be aware of the date, the intended meaning might be something like Make sure you check the deadline before submitting the application.

That would also be correct, but the tone would change.

• Vær opmærksom på datoen... = direct instruction / advice
• Du skal være opmærksom på datoen... = You must/should be aware of the date...

The version with Vær is shorter and more typical for notices and instructions. The version with du skal sounds a bit more explicit and can feel more personal or stronger depending on context.

A few things may be difficult for English speakers:

• Vær: the vowel is not like English bear, even though it may look similar.
• opmærksom: this word has the Danish letter æ, and the stress is usually on mærk-like part: op-MÆRK-som.
• datoen: often pronounced smoothly, with the ending not strongly separated.
• ansøgningen: this is a long word, and Danish tends to reduce some unstressed syllables in natural speech.

Also, Danish spoken rhythm often makes words sound more connected than their spelling suggests, so listening practice is especially helpful with sentences like this.

Not usually. Notice the date in English can sound like observe that there is a date or look at the date. Danish Vær opmærksom på datoen is broader and usually means:

• Be aware of the date
• Pay attention to the date
• Make sure you check the date

So notice is usually too narrow unless the context is specifically about visually spotting it.