Jeg øver mig på at danne en dansk sætning.

Because at øve sig is a very common reflexive construction in Danish when you mean to practice in a general sense.

• Jeg øver mig = I am practicing / I practice
• Jeg øver by itself often sounds incomplete, as if you are practicing something specific and should say what it is.

The word mig is the reflexive pronoun here, matching jeg:

• jeg → mig
• du → dig
• han/hun → sig

So Jeg øver mig på ... means I am practicing ...

In this sentence, på is the preposition that goes naturally with øve sig when talking about what you are practicing.

So:

• øve sig på noget = practice something
• øve sig på at ... = practice doing ...

In English, we might say:

• I practice forming a Danish sentence
• I practice making a Danish sentence

But in Danish, the structure is commonly:

• Jeg øver mig på at ...

So på is not being translated word-for-word as on here. It is just part of the Danish pattern.

Because at is the infinitive marker in Danish, similar to to in English.

• at danne = to form
• at skrive = to write
• at lære = to learn

After øve sig på, Danish often uses:

• på at + infinitive

So:

• Jeg øver mig på at danne ... = I am practicing forming ...

This is one of the most useful patterns to remember.

Because after at, Danish uses the infinitive form of the verb.

• at danne = infinitive, to form
• danner = present tense, form/forms

So:

• Jeg danner en sætning = I form a sentence
• Jeg øver mig på at danne en sætning = I practice forming a sentence

The -e form is normal after at.

Because sætning is a common gender noun in Danish, so it takes en, not et.

• en sætning = a sentence
• sætningen = the sentence

Danish nouns have grammatical gender:

• en-words = common gender
• et-words = neuter

You simply have to learn which article goes with each noun.

Because dansk is describing an en-word in the indefinite singular: en sætning.

With many adjectives in Danish:

• en + adjective + noun → base form of the adjective
• et + adjective + noun → often add -t
• plural/definite forms → often add -e

So:

• en dansk sætning
• et dansk ord
• danske sætninger

Here, sætning is an en-word, so dansk stays in its basic form.

Sometimes, but the nuance is a bit different.

• danne = form
• lave = make
• skrive = write

In this sentence, danne en sætning sounds natural if you mean to form/build a sentence.

Depending on what you want to emphasize, you could also hear:

• Jeg øver mig på at skrive danske sætninger = I practice writing Danish sentences
• Jeg øver mig på at lave sætninger på dansk = I practice making sentences in Danish

So danne is fine, but it is not the only possible choice.

In normal Danish noun phrases, adjectives usually come before the noun, just as in English.

• en dansk sætning
• et stort hus
• en god bog

So dansk comes before sætning because it is describing the noun.

Danish can place descriptive information after the noun in other sentence types, but not in this basic adjective + noun structure.

Because Danish main clauses normally use Verb Second word order, and when the subject comes first, the structure is:

• Subject + verb + ...

So:

• Jeg øver mig på at danne en dansk sætning.

Here:

• Jeg = subject
• øver = finite verb

This is the most basic and neutral word order.

If you move something else to the front, the verb still stays in second position:

• I dag øver jeg mig på at danne en dansk sætning.

Notice that øver still comes second.

Yes. øver is the present tense form of øve.

• jeg øver = I practice / I am practicing

Danish present tense often covers both:

• I practice
• I am practicing

The exact meaning depends on context.

Yes, but it most directly means practicing forming a Danish sentence, that is, one sentence or a sentence as an example.

If you want to speak more generally, Danish often prefers the plural:

• Jeg øver mig på at danne danske sætninger. = I practice forming Danish sentences.

So the singular is grammatical and natural, but the plural may sound more general.

Not exactly. Mig is the object/reflexive form used with jeg, but Danish reflexive usage does not always match English word-for-word.

In English, we often say:

• I practice
• I practice forming sentences

But Danish often says:

• Jeg øver mig ...

So mig is functioning reflexively, but you should think of øve sig as a set expression rather than translating myself literally every time.

A few common variations could sound even more natural depending on context:

• Jeg øver mig på at skrive danske sætninger.

  • I’m practicing writing Danish sentences.

• Jeg øver mig i at danne danske sætninger.

  • I’m practicing forming Danish sentences.

• Jeg øver mig i dansk.

  • I’m practicing Danish.

Your original sentence is understandable and grammatical, but learners will also often hear øve sig i and plural nouns like danske sætninger in very natural usage.