Jeg skal bruge en bestemt bog til kurset.

In this sentence, skal + bruge works as a very common Danish way to express need.

• skal by itself often means shall / must / have to
• bruge by itself often means use

But together, skal bruge often means something like:

• need
• will need
• have to use

So Jeg skal bruge en bestemt bog is a natural way to say that the speaker needs that book for a purpose.

Because skal is a modal verb.

After Danish modal verbs, the next verb comes in the bare infinitive, without at.

Common modal verbs include:

• kan
• skal
• vil
• må
• bør

So you say:

• Jeg skal bruge ...

not

• Jeg skal at bruge ...

This is similar to English I can go, not I can to go.

It can mean both, depending on the structure.

• Jeg bruger en bog = I use a book
• Jeg skal bruge en bog = I need a book / I will need a book

So the meaning of bruge becomes more like need when it appears in the expression skal bruge.

En bestemt bog means a certain book or a specific book.

The important idea is that it is:

• one particular book
• but still in the indefinite form

So the speaker has a specific book in mind, even if it has not been named in the sentence.

This is a very important Danish distinction.

• en bestemt bog = a certain / a specific book
• den bestemte bog = the specific / the particular book

So:

• en bestemt bog is indefinite
• den bestemte bog is definite

A learner can think of it like this:

• en bestemt bog: there is one specific book, but it is introduced as new information
• den bestemte bog: we already know which book is meant, or it has been identified already

Because bog is a common gender noun in Danish.

Danish nouns are mainly divided into two genders:

• common gender → takes en
• neuter gender → takes et

So you must learn the noun together with its article:

• en bog
• et hus
• et kursus

That is why the sentence has en bestemt bog.

Here, bestemt is an adjective meaning specific / certain.

In Danish, adjectives usually agree with the noun in form, but bestemt already has the shape used here. So en bestemt bog is the correct form.

Also, do not confuse the everyday meaning of bestemt here with grammatical terminology:

• in grammar, bestemt can mean definite
• in normal vocabulary, it can mean specific, certain, or sometimes determined, depending on context

In this sentence, it means specific / certain.

Because til is the natural preposition here.

Til kurset means something like:

• for the course
• for use in the course
• for class

In Danish, til is often used when something is intended for a purpose, event, or activity.

For kurset would usually sound less natural here and could suggest a different relationship, depending on context.

So til kurset is the normal choice for for the course.

Because kurset is the definite singular form of et kursus.

• et kursus = a course
• kurset = the course

In Danish, the definite article is often added to the end of the noun instead of being a separate word.

So English:

• the course

becomes Danish:

• kurset

That is why the sentence says til kurset = for the course.

The word order is very standard for a Danish main clause:

• Jeg = subject
• skal = finite verb
• bruge = infinitive
• en bestemt bog = object
• til kurset = prepositional phrase

So the pattern is:

Subject + finite verb + infinitive + object + other information

This also shows the Danish V2 rule in a simple way: in a main clause, the finite verb normally comes in the second position.

For example, you can move Til kurset to the front, but then skal still stays second:

• Til kurset skal jeg bruge en bestemt bog.

A bit of both, depending on context.

Skal often expresses:

• obligation
• necessity
• something expected in the future

In this sentence, it most naturally suggests necessity:

• the speaker needs a certain book for the course

But in English, the best translation might be:

• I need a specific book for the course
• I’ll need a specific book for the course

So skal does not always correspond neatly to just one English word.

Yes. A very common alternative is:

• Jeg har brug for en bestemt bog til kurset.

This literally looks like I have use for, but it means I need.

Both are natural, but they can feel slightly different:

• Jeg skal bruge ... = often practical, situational, sometimes I’m going to need
• Jeg har brug for ... = a very direct way to say I need

Both are useful, and you will hear both often.