Hún prjónar með mjúku garni á kvöldin meðan hún hlustar á hljóðbók.

It has two parts:

• Main clause: Hún prjónar með mjúku garni á kvöldin
• Subordinate clause: meðan hún hlustar á hljóðbók

A quick breakdown:

• Hún = subject, she
• prjónar = verb, knits
• með mjúku garni = prepositional phrase, with soft yarn
• á kvöldin = time expression, in the evenings
• meðan hún hlustar á hljóðbók = while she listens to an audiobook

So the sentence is built as:

She knits + with soft yarn + in the evenings + while she listens to an audiobook

Prjónar is the 3rd person singular present tense of the verb prjóna, meaning to knit.

So:

• að prjóna = to knit
• ég prjóna = I knit
• hún prjónar = she knits

This matches the subject hún.

Because the preposition með takes the dative case.

The noun is:

• garn = yarn, thread

Its basic form is garn, but after með it changes to the dative singular:

• með garni = with yarn

So:

• garn = nominative/accusative form
• garni = dative form

This is very common in Icelandic: many prepositions require a specific case.

Because Icelandic adjectives must agree with the noun they describe in:

• gender
• number
• case

Here, garn is:

• neuter
• singular
• dative (because of með)

So the adjective mjúkur changes to the matching form:

• mjúku

That gives:

• með mjúku garni = with soft yarn

If the noun were in a different case or gender, the adjective form would change too.

Með normally takes the dative.

So in this sentence:

• með mjúku garni

both the adjective and noun are in the dative:

• mjúku = dative form of the adjective
• garni = dative form of the noun

For learners, it is useful to remember með + dative as a set pattern.

Á kvöldin is a common Icelandic time expression meaning in the evenings or at night/evenings regularly.

A few important points:

• kvöld = evening
• kvöldin = the evenings
• á kvöldin is an idiomatic expression for a habitual/repeated time

So here it means something like:

• in the evenings
• during evenings as a regular habit

It is not best translated word-for-word. Even though it literally looks like on the evenings, the natural English meaning is in the evenings.

Meðan means while.

It introduces a subordinate clause that tells you what is happening at the same time as the main action:

• meðan hún hlustar á hljóðbók
• while she listens to an audiobook

So the sentence describes two simultaneous actions:

• she knits
• she listens to an audiobook

In Icelandic, hlusta usually goes with the preposition á when it means listen to.

So:

• hlusta á tónlist = listen to music
• hlusta á útvarpið = listen to the radio
• hlusta á hljóðbók = listen to an audiobook

This is one of those verb + preposition combinations that you simply need to learn.

So even though English says listen to, Icelandic says:

• hlusta á

Because although hlusta á takes the accusative, the noun hljóðbók happens to look the same in that form.

So grammatically, it is accusative here, but the written form is still:

• hljóðbók

This is very common in Icelandic: sometimes a noun changes clearly between cases, and sometimes the form stays the same.

So here:

• á hljóðbók = accusative after hlusta á
• but the visible form is still hljóðbók

Because Icelandic normally uses an explicit subject in each clause.

So you get:

• Hún prjónar ...
• meðan hún hlustar ...

In English, we also usually repeat she here:

• She knits ... while she listens ...

So the repeated hún is completely normal and natural.

Icelandic does not have a separate progressive tense like English is knitting or is listening.

The present tense can cover both:

• general/habitual action
• action happening now

Here, the phrase á kvöldin makes the meaning clearly habitual:

• Hún prjónar ... á kvöldin = she knits in the evenings

So in this sentence, the present tense is best understood as a regular habit, not a one-time action happening right now.

Yes. If the subordinate clause comes first, the main clause follows normal Icelandic verb-second word order.

So you would say:

• Meðan hún hlustar á hljóðbók, prjónar hún með mjúku garni á kvöldin.

Notice the order in the main clause:

• prjónar hún
• not hún prjónar

That happens because the first position in the sentence is already occupied by the meðan clause.