Hún vill frekar smyrja sultu á brauðið en rista það.

Here frekar means rather or preferably. In the pattern vilja frekar X en Y, it expresses a preference between two actions: doing X rather than Y.

So in this sentence, frekar shows that spreading jam is the preferred option, compared with toasting the bread.

Yes. Even though vill literally means wants, the combination vill frekar is very naturally translated as would rather or prefers to, depending on context.

So:

• Hún vill frekar... = She would rather...
• or She prefers to...

A very literal translation may sound a bit stiff in English, so a more natural English meaning is often better.

Vill is the 3rd person singular present form of the irregular verb vilja, meaning to want.

A few present-tense forms are:

• ég vil = I want
• þú vilt = you want
• hún/hann/það vill = she/he/it wants

So Hún vill means she wants.

Because vilja normally takes a bare infinitive after it. That means the next verb appears in the infinitive without að.

So:

• Hún vill smyrja...
• Hún vill rista...

This is similar to English she wants to spread, except Icelandic does not use the infinitive marker here after vilja.

Sultu is the accusative singular of sulta, meaning jam.

It appears in the accusative because it is the direct object of smyrja: it is the thing being spread.

Compare:

• sulta = nominative singular
• sultu = accusative singular
• sultan / sultuna would be the definite form, depending on case

So sultu here means jam in an indefinite sense, not the jam.

The preposition á can take either the accusative or the dative, depending on meaning.

• accusative: movement toward a surface, or something being put onto it
• dative: location on a surface

Here the jam is being spread onto the bread, so Icelandic uses the accusative:

• á brauðið

If you were only describing location, you would expect:

• á brauðinu = on the bread

Because Icelandic usually attaches the definite article to the end of the noun instead of writing a separate word like English the.

So:

• brauð = bread
• brauðið = the bread

That ending -ið is the definite article here.

Það means it, and it refers back to brauðið.

It is það specifically because brauð is a neuter noun, and the pronoun has to match it in gender and number. Here it is also the object of rista, so the correct pronoun is það.

So:

• rista það = toast it

Here en means than.

After words like frekar, Icelandic uses en to introduce the second part of the comparison:

• frekar X en Y = rather X than Y

So in this sentence, en rista það means than toast it.

The sentence follows normal Icelandic main-clause word order, where the finite verb usually comes in the second position.

Structure:

• Hún = subject
• vill = finite verb
• frekar = adverb
• smyrja sultu á brauðið = first infinitive phrase
• en rista það = second infinitive phrase for comparison

So the core pattern is:

• Subject + finite verb + adverb + infinitive phrase + en + infinitive phrase

That is why vill appears very early in the sentence.