Hljómsveitin spilar fyrsta lagið núna.

In Icelandic, the is usually added to the end of the noun instead of written as a separate word.

So here:

• hljómsveit = band
• hljómsveitin = the band

and

• lag = song
• lagið = the song

So the sentence contains two definite nouns: hljómsveitin and lagið.

Spilar is the present tense, 3rd person singular form of the verb spila.

Why 3rd person singular?

• the subject is hljómsveitin = the band
• the band is grammatically singular
• so the verb must also be singular: spilar

A few forms of spila:

• ég spila = I play
• þú spilar = you play
• hann / hún / það spilar = he / she / it plays
• við spilum = we play

Its basic form is simple present, so literally it is plays.

But in translation, English often uses is playing because the sentence has núna = now, which makes the action feel current and ongoing.

So:

• grammatical Icelandic form: spilar
• natural English meaning in context: is playing

If you want to emphasize an action that is happening right now, Icelandic also often uses vera að + infinitive, for example er að spila.

Because fyrsti / fyrsta / fyrstu must agree with the noun it describes.

Here the noun is lagið, and lag is:

• neuter
• singular
• here functioning as the direct object

So the matching form is fyrsta.

Ordinal numbers such as first, second, third behave like adjectives in Icelandic, so they change form to match the noun.

It is accusative, because it is the direct object of spilar.

The band does the action, and the first song is what gets played, so fyrsta lagið is the object.

A useful detail: with many neuter singular nouns, nominative and accusative look the same. So even though lagið is accusative here, its form is identical to the nominative form.

The same is true for fyrsta in this phrase: the form does not visibly change here, even though the phrase is functioning as an accusative object.

Usually, you learn noun gender from a dictionary or from repeated exposure, because Icelandic gender is not always predictable from meaning.

In this sentence:

• hljómsveit is feminine
• lag is neuter

The definite endings help show that:

• hljómsveitin has a feminine definite ending
• lagið has a neuter definite ending

So gender matters because it affects:

• the form of the article
• adjective agreement
• sometimes pronouns and other parts of the sentence

Yes, núna can move.

In this sentence, the order is a very straightforward:

• subject: Hljómsveitin
• verb: spilar
• object: fyrsta lagið
• time adverb: núna

That is a natural and common order.

You can also front núna for emphasis:

• Núna spilar hljómsveitin fyrsta lagið.

Notice that the verb spilar still comes second. That is an important Icelandic main-clause pattern: the finite verb is typically in second position.

It is a bit tricky for English speakers, especially the beginning hlj- cluster.

A rough English-friendly approximation is:

HLYOHM-svay-tin

A few notes:

• hlj is not pronounced like a normal English hlj cluster
• the l is voiceless at the beginning
• jó sounds roughly like yoh
• ei in -sveit- sounds like ay in day

You do not need a perfect pronunciation immediately; the hardest part is the beginning of the word.