Han er nervøs før daten.

Because Danish usually marks the by adding it to the end of the noun.

• en date = a date
• daten = the date

So Danish does not need a separate word like English the here. The ending -en is the definite article for many common-gender nouns.

Yes. Date is a common modern Danish loanword, especially in informal speech, and it means a romantic date.

You may also come across other expressions, but en date / daten is very normal in everyday Danish.

Because Danish uses være (to be) with adjectives in sentences like this.

• Han er nervøs = He is nervous

Here, nervøs is an adjective describing han. This works just like English is nervous.

You would not use have here in Danish the way some other languages might.

Because the subject is han, and with a singular common-gender subject, the adjective often stays in its basic form.

So:

• Han er nervøs = basic form
• Barnet er nervøst = neuter singular
• De er nervøse = plural

That means nervøs changes in some contexts, but in this sentence the basic form is the correct one.

Here, før means before in a time sense.

So før daten means before the date.

A useful thing to remember:

• før = before in time
• foran = in front of in space

So if you want to talk about time, før is the right word here.

Sometimes, yes, but før daten is the most straightforward and natural choice here.

Both før and inden can relate to before, but they are not always used in exactly the same way. In a simple sentence with a noun phrase like this, før is the safest option.

You will often hear inden in expressions like:

• inden da = before then
• inden daten begynder = before the date begins

So for this exact sentence, før daten is the best model to learn first.

Because this is the normal Danish main-clause order:

subject + verb + adjective/complement + time expression

So:

• Han = subject
• er = verb
• nervøs = description
• før daten = time phrase

This is a very standard Danish sentence pattern.

In the present tense, er stays the same for all persons.

For example:

• Jeg er nervøs
• Du er nervøs
• Han er nervøs
• Vi er nervøse
• De er nervøse

So unlike English, Danish does not have different present-tense forms like am / is / are. It just uses er.

Yes. That means something like He feels nervous before the date.

Compare:

• Han er nervøs før daten = simple, direct description
• Han føler sig nervøs før daten = emphasizes how he feels

Both are correct, but Han er nervøs før daten is the simpler and more basic structure.

Yes, slightly.

• før daten = before the date
  This refers to a specific date, one that is known from the context.

• før en date = before a date
  This sounds more general or indefinite.

So the sentence you were given points to a particular date, not just any date.