Ölen är kall.

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

• öl = beer
• ölen = the beer

In this sentence, -en is the definite ending.

Öl is a word you may see in more than one pattern.

In everyday Swedish, especially when talking about a beer as a drink, en öl and ölen are very common. But you may also see ett öl and ölet.

That means both of these can occur:

• Ölen är kall.
• Ölet är kallt.

The sentence you have uses the en-word version.

Är is the present tense of vara, which means to be.

So är can mean am, are, or is, depending on the subject:

• jag är = I am
• du är = you are
• ölen är = the beer is

It is an irregular verb, so you just have to learn the form är.

Because Swedish adjectives agree with the noun in gender and number, even when they come after är.

Here is the basic pattern:

• common gender singular: kall
• neuter singular: kallt
• plural: kalla

Since this sentence uses ölen as a singular en-word, the adjective is kall.

Compare:

• Ölen är kall.
• Ölet är kallt.
• Dryckerna är kalla.

Because Swedish usually does not use a separate word like English the in cases like this. Instead, definiteness is attached to the noun itself.

So:

• öl = beer
• ölen = the beer

That is why the sentence does not need an extra word before ölen.

A rough guide is:

• ölen ≈ EU-len, but with rounded lips on the first vowel
• är ≈ air
• kall ≈ kahl

A more exact pronunciation is roughly:

• ölen: /ˈøːlɛn/
• är: /ɛːr/ or /æːr/
• kall: /kal/

Two important vowel notes:

• ö is not a normal English vowel. Try saying something like the vowel in bird, but with rounded lips.
• ä is often roughly like the vowel in air.

You put the verb first:

Är ölen kall?

That means Is the beer cold?

This is a very common pattern in Swedish yes/no questions: the verb comes before the subject.

Then the adjective goes before the noun, and Swedish uses double definiteness.

With the form in your sentence, you get:

• den kalla ölen

If you use the ölet version instead, you get:

• det kalla ölet

So:

• Ölen är kall. = the beer is cold
• den kalla ölen = the cold beer

The adjective changes form because it is now placed before the noun.