Eftir sturtuna þurrkar hún spegilinn með viskustykki, því raki safnast þar fljótt.

This is a very common Icelandic pattern: the finite verb usually comes in second position in a main clause.

So when the sentence starts with Eftir sturtuna (After the shower), that first phrase takes the first slot, and the verb þurrkar moves into the second slot:

• Eftir sturtuna þurrkar hún spegilinn.

If you started with the subject, you would get:

• Hún þurrkar spegilinn eftir sturtuna.

Both are possible, but the sentence given puts emphasis on when she does it.

Here eftir means after in a time expression, and in that use it takes the accusative.

So:

• sturta = shower
• sturtuna = the shower in the accusative singular

That is why you get:

• eftir sturtuna = after the shower

This is worth remembering because Icelandic prepositions often control a specific case, and some can take different cases depending on meaning.

In Icelandic, the definite article is usually attached to the end of the noun as a suffix.

So:

• sturta = shower
• sturtan / sturtuna = the shower

and

• spegill = mirror
• spegillinn / spegilinn = the mirror

The exact ending depends on the noun’s gender, number, and case.

So Icelandic often expresses the by changing the noun itself, not by adding a separate word like English the.

Spegilinn is the direct object of þurrkar (dries/wipes), so it appears in the accusative.

The noun is:

• spegill = mirror

Its accusative singular is spegil, and with the definite article added, it becomes:

• spegilinn = the mirror

So:

• þurrkar spegilinn = dries/wipes the mirror

Þurrkar is the present tense, 3rd person singular form of the verb þurrka.

So:

• ég þurrka = I dry / wipe
• þú þurrkar = you dry / wipe
• hún þurrkar = she dries / wipes

In this sentence, it matches hún (she), so þurrkar means dries or wipes.

The preposition með (with) takes the dative.

So viskustykki is in the dative here. The reason it may not look different is that this neuter noun has the same form in several cases in the singular.

So:

• með viskustykki = with a dishcloth / tea towel

It is also indefinite here, because the sentence just means she uses a dishcloth as the tool or instrument, not necessarily the specific dishcloth.

Here því means because or since.

It introduces the reason:

• ..., því raki safnast þar fljótt.
• ..., because moisture gathers there quickly.

This word can be tricky because því can have other uses in Icelandic too, but in this sentence it is best understood as a conjunction giving the reason for wiping the mirror.

Safnast comes from the verb safna, which is related to gathering or collecting.

The -st form often gives a meaning like:

• happens by itself
• becomes passive-like
• is intransitive or reflexive in feel

So:

• safna can mean to collect / gather
• safnast means to collect, gather, accumulate

In this sentence:

• raki safnast = moisture accumulates / gathers

So the idea is not that someone is actively collecting the moisture, but that it builds up on its own.

Because raki here refers to moisture in a general sense, like a mass noun.

So:

• raki = moisture / dampness / humidity

English also often does this with uncountable nouns:

• Water collects there
• Moisture forms there

If Icelandic used rakinn, it would sound more like the specific moisture already identified in context. Here the general noun is more natural.

Þar usually means there.

In this sentence, it refers back to the mirror or its surface:

• raki safnast þar fljótt = moisture gathers there quickly

In natural English, you might sometimes translate it more freely as on it or there on the mirror, even though Icelandic simply uses þar.

Because fljótt is an adverb, and it modifies the verb safnast.

• fljótur = quick / fast (adjective)
• fljótt = quickly / fast (adverb)

So:

• raki safnast fljótt = moisture gathers quickly

If you used fljótur, that would describe a noun, not the action.

It can naturally suggest either, depending on context.

Literally it is after the shower, but in everyday use that often corresponds to English after showering or after taking a shower.

So in this sentence, the idea is simply the time right after she has showered, when the mirror has become wet or foggy.