Delbetalningen minskar skulden.

It is a compound noun:

• del = part
• betalning = payment

So delbetalning means something like partial payment or installment payment.

Then the ending -en is added to make it definite:

• en delbetalning = a partial payment / an installment payment
• delbetalningen = the partial payment / the installment payment

Swedish uses compound nouns very freely, much more than English.

Because Swedish often puts the definite article on the end of the noun instead of using a separate word like the.

Here the base noun is:

• en delbetalning = an installment payment

Its definite singular form is:

• delbetalningen = the installment payment

So -en here is the definite ending for a common-gender noun.

For the same reason: skuld is also a common-gender noun.

• en skuld = a debt
• skulden = the debt

So the sentence uses two definite nouns:

• delbetalningen = the installment payment
• skulden = the debt

In Swedish, this is completely normal. You do not need a separate word for the in these simple cases.

Because Swedish usually expresses definiteness by adding an ending to the noun.

Compare:

• en skuld = a debt

• skulden = the debt

• en delbetalning = an installment payment
• delbetalningen = the installment payment

English uses a separate article, but Swedish often uses a suffix instead.

A separate definite word such as den is used in other situations, especially with adjectives:

• den stora skulden = the big debt

But without an adjective, the suffix alone is enough:

• skulden

Minskar is the present tense of the verb minska, which means to decrease, to reduce, or to diminish depending on context.

So:

• minska = infinitive, to reduce / to decrease
• minskar = present tense, reduces / decreases

In this sentence, minskar means reduces.

Many Swedish verbs form the present tense by adding -r to the infinitive:

• minska → minskar
• betala → betalar
• öka → ökar

In this sentence, word order tells you:

• Delbetalningen = subject
• minskar = verb
• skulden = object

So the structure is:

• Subject + Verb + Object

That is the same basic order as in English:

• The installment payment reduces the debt

Swedish does not usually mark subject and object with special noun endings the way some other languages do, so word order is very important.

Yes, in this sentence it is very similar to English:

• Delbetalningen minskar skulden
• The installment payment reduces the debt

This is a straightforward main clause with normal word order.

However, Swedish has an important general rule called V2: in main clauses, the finite verb usually comes in the second position. In this sentence, that rule is satisfied naturally because the subject comes first:

• Delbetalningen = position 1
• minskar = position 2

So this sentence is simple, but it also fits an important Swedish pattern.

The dictionary forms are:

• delbetalning = installment payment / partial payment
• skuld = debt
• minska = to reduce / to decrease

If you are learning vocabulary, it helps to store Swedish nouns with their gender word:

• en delbetalning
• en skuld

That makes it easier to form the definite versions later:

• delbetalningen
• skulden

Most directly, delbetalning refers to a payment made in parts, often an installment payment or partial payment.

Depending on context, Swedish can also use delbetalning in the broader area of paying by installments. But in this sentence, because the noun is singular and definite — delbetalningen — it most naturally refers to one specific installment payment.

So here it is best understood as:

• the installment payment or
• the partial payment

Using skulden makes the debt specific or known.

Compare:

• Delbetalningen minskar en skuld = The installment payment reduces a debt
• Delbetalningen minskar skulden = The installment payment reduces the debt

The definite form suggests that the speaker and listener know which debt is being talked about, or that it is the debt already under discussion.

So the definite form is not random; it gives the noun a more specific meaning.

Yes. In Swedish, minska can be used transitively, meaning it can directly affect something:

• minska kostnaderna = reduce the costs
• minska risken = reduce the risk
• minska skulden = reduce the debt

It can also be used intransitively:

• Kostnaderna minskar = The costs decrease

So in your sentence, minskar skulden is a normal and correct transitive use.