Metallen blir varm i solen.

Because metallen is the definite singular form of en metall.

• en metall = a metal
• metallen = the metal

In Swedish, the definite article is usually attached to the end of the noun as a suffix:

• en bok → boken
• en bil → bilen
• en metall → metallen

So -en here means the.

Blir means becomes or gets, while är means is.

So:

• Metallen blir varm i solen = the metal gets/becomes warm in the sun
• Metallen är varm i solen = the metal is warm in the sun

Using blir focuses on a change of state: the metal was not warm before, but the sun makes it warm.

Because metallen is a singular common-gender noun, and adjectives match that form.

Here are the basic forms of varm:

• en metall → varm
• ett hus → varmt
• plural → varma

So:

• metallen blir varm
• huset blir varmt
• metallerna blir varma

Since metall is an en-word, varm is correct.

I solen means in the sun.

Swedish often uses i in places where English also says in, but the exact usage does not always match word-for-word. With solen, i solen is the normal way to say in the sun or in sunlight.

So even though English speakers might think of on or something more literal, Swedish idiomatically says:

• sitta i solen = sit in the sun
• bli varm i solen = get warm in the sun

Because Swedish usually uses the definite form here: solen = the sun.

• en sol = a sun
• solen = the sun

Just like metallen, the definite article is added as a suffix:

• sol
  • -en → solen

In this sentence, Swedish wants the specific sun, so solen is the natural choice.

The sentence follows normal Swedish main-clause word order:

Subject + verb + complement + adverbial

• Metallen = subject
• blir = verb
• varm = subject complement
• i solen = adverbial phrase

So:

Metallen blir varm i solen.

This is very similar to English: The metal gets warm in the sun.

Yes. Swedish often allows another element to come first, but then the verb must stay in second position.

So you can say:

I solen blir metallen varm.

That still means the same thing, but now i solen is emphasized a bit more.

Notice the word order change:

• Metallen blir varm i solen
• I solen blir metallen varm

This is a good example of Swedish V2 word order: in main clauses, the finite verb usually comes second.

Yes, but the meaning changes slightly.

• Metallen blir varm i solen = the metal gets/becomes warm in the sun
• Metallen är varm i solen = the metal is warm in the sun

So blir describes the process or result of heating up, while är just describes the state.

It is an en-word:

• en metall
• metallen

That is why the adjective is varm, not varmt.

This is worth memorizing, because gender affects both the noun form and adjective agreement.

A simple learner-friendly pronunciation is roughly bleer.

A few notes:

• the i is a long vowel here
• the r is pronounced, but how strong it sounds depends on dialect
• in normal speech, blir is often said very smoothly and quickly

A rough full-sentence pronunciation guide could be:

meh-TAH-len bleer varm ee SOH-len

That is only approximate, but it can help you get started.

As written, metallen sounds like a specific metal object/substance already known in context: the metal.

If you wanted to talk about metal more generally, Swedish might use a different structure, for example:

• Metall blir varm i solen is not the most natural general statement
• more naturally, you might say something like Metall blir varm i solen only in special contexts, but Swedish often prefers a more specific or different phrasing

So in this sentence, metallen most naturally means a particular metal item or the metal being discussed.