Räntan ökar kostnaden för lånet.

A word-by-word breakdown:

• räntan = the interest / the interest rate
• ökar = increases
• kostnaden = the cost
• för = of / for, depending on context
• lånet = the loan

So the sentence means something like:

The interest increases the cost of the loan.

In natural financial English, you might also say:

• Interest increases the cost of the loan
• The interest rate increases the cost of the loan

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

Here:

• ränta = interest

• räntan = the interest

• kostnad = cost

• kostnaden = the cost

• lån = loan
• lånet = the loan

So those endings are doing the job of English the.

This is because Swedish nouns belong to different grammatical genders.

• ränta is an en-word
• kostnad is an en-word
• lån is an ett-word

In the singular definite form:

• many en-words take -en or -n
• many ett-words take -et or -t

So:

• en ränta → räntan
• en kostnad → kostnaden
• ett lån → lånet

You mostly have to learn whether a noun is an en word or an ett word when you learn the noun.

Because Swedish verbs do not change according to the subject the way English verbs sometimes do.

In English:

• I increase
• he increases
• they increase

In Swedish, the present tense form is the same for all persons:

• jag ökar
• du ökar
• han/hon ökar
• vi ökar
• de ökar

So ökar is simply the present tense form of öka = to increase.

In a normal Swedish statement, the basic word order is:

Subject + verb + object

So here:

• Räntan = subject
• ökar = verb
• kostnaden för lånet = object

That means the interest is doing the action, and the cost of the loan is what is being increased.

In this sentence, för links kostnaden to lånet and means something like of in English.

So:

• kostnaden för lånet = the cost of the loan

This is a very common pattern in Swedish:

• priset för bilen = the price of the car
• kostnaden för projektet = the cost of the project
• ansvaret för barnen = the responsibility for the children

Even though för often means for, in many expressions English would naturally translate it as of.

Yes. Swedish often likes compound nouns.

A very natural alternative would be:

Räntan ökar lånekostnaden.

That means the same thing: The interest increases the cost of the loan.

Here:

• låne- = loan-
• kostnaden = the cost

So lånekostnaden = the loan cost / the cost of the loan

Both versions are understandable. Swedish often prefers compounds, especially in formal or financial language.

Because in Swedish, the definite meaning is usually built into the noun itself.

So instead of:

• the loan

Swedish often says:

• lånet

not usually den lånet

However, Swedish can use a separate definite word together with an adjective:

• det stora lånet = the big loan
• den höga räntan = the high interest rate

So:

• without adjective: lånet
• with adjective: det stora lånet

No. Ränta means financial interest or interest rate.

So it is used in contexts like:

• hög ränta = high interest rate
• betala ränta = pay interest

It does not mean interest in the sense of curiosity or personal enthusiasm. For that, Swedish uses words like:

• intresse = interest, curiosity, interest as a hobby/topic

So:

• Jag har ett stort intresse för musik = I have a great interest in music
• Räntan är hög = The interest rate is high

A rough pronunciation guide for an English speaker:

• Räntan ≈ REN-tan
  The ä sounds somewhat like the e in bed, though not exactly.

• ökar ≈ UR-kar or ER-kar
  The ö does not have an exact English equivalent. It is a rounded vowel.

• kostnaden ≈ KOST-nah-den

• för ≈ fur but with rounded lips
  Again, ö is not a normal English vowel.

• lånet ≈ LOH-net

A more important point than perfect imitation is to notice the Swedish vowels ä and ö, since English speakers often confuse them.

Most directly, it sounds like it is talking about a specific loan or the loan being discussed, because of the definite form:

• räntan = the interest
• kostnaden = the cost
• lånet = the loan

In context, though, Swedish sometimes uses definite forms in a more general or institutional way than English does. So depending on the situation, it could also be understood as a general statement about how interest affects loan cost.

If you wanted a more clearly general statement, you might also see something like:

• Ränta ökar kostnaden för lån in a headline-like style
• Räntor ökar kostnaden för lån = Interest rates increase the cost of loans

Sometimes, yes.

The Swedish present tense can often correspond to:

• English simple present: increases
• English present progressive: is increasing

So depending on context:

• Räntan ökar kostnaden för lånet can mean The interest increases the cost of the loan
• In some contexts, it could also be interpreted more dynamically as The interest is increasing the cost of the loan

Usually, the surrounding context tells you which English version sounds most natural.

The dictionary forms are:

• ränta = interest / interest rate
• öka = to increase
• kostnad = cost
• lån = loan

The sentence uses inflected forms:

• ränta → räntan
• öka → ökar
• kostnad → kostnaden
• lån → lånet

This is very useful to notice when using a dictionary, because you usually need the base form, not the form from the sentence.

Yes, but the original Swedish order is already perfectly normal Swedish.

A few possible rephrasings in Swedish are:

• Räntan ökar kostnaden för lånet.
• Räntan gör lånet dyrare. = The interest makes the loan more expensive.
• Räntan höjer kostnaden för lånet. = The interest raises the cost of the loan.

These are slightly different in style, but the original sentence is clear and standard.