Aðstandandinn annast lyfjaskömmtunina.

Because Icelandic usually attaches the definite article to the end of the noun.

• aðstandandi = an attendant / next of kin / caregiver
• aðstandandinn = the attendant / next of kin / caregiver

Here, -inn is the definite ending. So Aðstandandinn is the subject and means the caregiver / the relative / the next of kin, depending on context.

It usually means someone closely connected to the person in question, often:

• a close relative
• next of kin
• a caregiver
• an attendant

The exact English word depends on context. In medical or care-related language, aðstandandi often refers to a family member or other close person who helps manage care.

Annast is the verb meaning to take care of, to manage, or to be responsible for.

In this sentence, it is in the present tense, so the sentence means that the caregiver/relative takes care of or is responsible for the medication dosing.

A useful thing to know is that annast is an -st verb. That -st is part of the verb itself; it is not a separate word. Verbs like this often look unusual to English speakers at first.

Because annast belongs to the group of Icelandic middle-voice / -st verbs. In the present tense singular, these verbs often keep the -st form.

So here:

• infinitive: að annast
• present singular: annast

That means Aðstandandinn annast ... is a normal present-tense clause, even though it may not look like the more familiar -r ending that many Icelandic verbs have in the 3rd person singular.

Because it is the direct object of annast, and annast takes the accusative case.

The base noun is:

• lyfjaskömmtun = medication dosing / dispensing

The form in the sentence is:

• lyfjaskömmtunina = the medication dosing / dispensing

The ending -ina shows that it is:

• definite
• singular
• accusative
• feminine

So the case is there because of the verb, and the definiteness is shown by the attached article.

Because Icelandic makes very frequent use of compound nouns, and they are usually written as a single word.

This word can be broken down roughly like this:

• lyfja- = medicine / medication-related
• skömmtun = dosing / dispensing
• -ina = the definite article in the accusative singular

So lyfjaskömmtunina is basically the medication-dosing or the dispensing of medication as one compound noun.

It is the compound form related to lyf, meaning medicine or drug.

In compounds, Icelandic often uses a linking form that comes from another case form of the noun. Here, lyfja- comes from the genitive plural of lyf.

You do not always need to analyze this every time you see a compound, but it helps to know that Icelandic compounds often include these linking forms.

There is no separate word for the here, because Icelandic often adds the definite article directly onto the noun.

In this sentence:

• Aðstandandinn = the caregiver / relative
• lyfjaskömmtunina = the medication dosing / dispensing

So both nouns are definite, and both show that by their endings.

Because lyfjaskömmtunina is the accusative form, while lyfjaskömmtunin would be the nominative form.

That difference matters because:

• subjects usually appear in the nominative
• direct objects often appear in the accusative

Here:

• Aðstandandinn is the subject
• lyfjaskömmtunina is the object

So -ina is the correct ending.

The sentence uses the most neutral word order:

• Subject – Verb – Object

So:

• Aðstandandinn annast lyfjaskömmtunina.

But Icelandic word order is somewhat flexible, as long as the verb stays in second position in a main clause.

For emphasis, you could also say:

• Lyfjaskömmtunina annast aðstandandinn.

That puts extra focus on lyfjaskömmtunina, but the verb annast still stays in second place.

You get a more indefinite or general meaning.

For example:

• aðstandandi = a caregiver / a relative
• lyfjaskömmtun = medication dosing / dispensing

With the definite endings, the sentence refers to a specific caregiver and a specific medication-dosing task or arrangement.

Without them, it would sound more general, less anchored to a specific situation.