De tror på kärleken.

In most modern spoken Swedish, de is usually pronounced dom.

So although it is written de, you will often hear:

• De tror på kärleken → Dom tror på kärleken

This is very common and normal in speech. In careful writing, though, de is still the standard subject form.

Tror is the present tense of the verb tro, which means to believe.

A few useful forms are:

• infinitive: tro
• present: tror
• past: trodde
• supine: trott

So de tror means they believe or they are believing, depending on context, though English usually just says they believe.

Because tro på is the usual expression for believe in.

So:

• tro på något = believe in something
• tro på kärleken = believe in love

This is different from plain tro, which often means think/believe that...

Compare:

• Jag tror att det är sant. = I think/believe that it is true.
• Jag tror på dig. = I believe in you.

Kärleken is the definite form of kärlek:

• kärlek = love
• kärleken = the love

In Swedish, abstract nouns are sometimes used in the definite form when talking about a big general idea in an idiomatic or almost symbolic way. So tro på kärleken is a very natural phrase meaning believe in love.

You may also see tro på kärlek, but tro på kärleken is especially common and idiomatic.

The ending -en is the definite article suffix.

In Swedish, the equivalent of English the is often attached to the noun itself:

• en bok = a book
• boken = the book

So:

• en kärlek = a love
• kärleken = the love

Since kärlek is an en-word, its definite singular form is kärleken.

Because Swedish usually puts the definite article at the end of the noun, not before it.

So English:

• the love

becomes Swedish:

• kärleken

A separate word like den is usually added only in certain structures, especially when there is an adjective:

• kärleken = the love
• den stora kärleken = the great love

No, this is a very basic Swedish main-clause pattern:

• De = subject
• tror = verb
• på kärleken = prepositional phrase

So the structure is:

Subject + verb + prepositional phrase

This is very similar to English:

• They believe in love.

Yes, in some contexts de can be part of expressions meaning those or can appear in more formal written language in other functions.

But in this sentence, de clearly means they, because it is the subject pronoun and is followed by the verb tror.

So here:

• De tror... = They believe...

A rough English-friendly approximation is:

SHAIR-leh-ken

A few notes:

• the k before ä is a soft k, sounding somewhat like sh
• the stress is on the first syllable: KÄR-lek-en
• the Swedish ä is not exactly the same as any single English vowel, but air is a useful approximation

So if you say something close to SHAIR-leh-ken, you will be in the right area.

Not exactly.

Tro på usually means believe in, have faith in, or have confidence in. In some contexts that can feel close to trust, but it is not the most direct translation of English trust.

So in this sentence, the idea is:

• They believe in love
• They have faith in love

rather than:

• They trust love

Yes, in informal writing, many people write dom because that matches normal pronunciation.

So:

• De tror på kärleken = standard written Swedish
• Dom tror på kärleken = informal spelling, common in casual contexts

If you are learning standard Swedish, it is best to write de here.