Endurnotkunin sparar hráefni.

It breaks down like this:

• endur- = again, re-
• notkun = use
• -in = the (the definite article attached to the noun)

So endurnotkunin literally means the reuse.

In Icelandic, the definite article is usually added to the end of the noun instead of being a separate word.

• endurnotkun = reuse
• endurnotkunin = the reuse

That is very normal Icelandic grammar.

The sentence is talking about reuse/recycling as a known general practice or concept, so the definite form is natural here.

English often uses a bare noun or gerund, as in Recycling saves raw materials, but Icelandic may use the definite noun where English would not.

It is:

• feminine
• singular
• nominative

It is in the nominative because it is the subject of the sentence.

Also, in Icelandic compounds, the gender usually comes from the last part of the word. Since notkun is feminine, endurnotkun is feminine too.

Sparar is the present tense, 3rd person singular form of spara.

It is singular because the subject, endurnotkunin, is singular.

Compare:

• endurnotkunin sparar = reuse/recycling saves
• endurnotkanirnar spara = the reuses save / the recycling methods save

Spara can mean save, spare, or conserve, depending on context.

So sparar hráefni can mean:

• saves raw materials
• spares raw materials
• conserves raw materials

It is a very common verb and is also used with things like money, time, energy, and effort.

It is a compound noun:

• hrár = raw
• efni = material, substance

So hráefni literally means raw material.

Like many Icelandic compounds, it is written as one word, not two.

Here hráefni is the direct object of spara, so it is in the accusative.

But the form does not visibly change here. That is common in Icelandic, especially with some neuter nouns. The same written form can appear in more than one case.

So even though it is accusative in function, it still looks like hráefni.

In this kind of sentence, hráefni is often understood as a mass noun or collective idea: raw material in general.

In English, that is often translated more naturally as raw materials.

So the Icelandic form may stay hráefni, while English prefers a plural translation.

Because it is being used generically.

The sentence is not talking about some specific raw materials already identified. It means raw materials in general, so an indefinite form is natural.

Strictly speaking, endurnotkun is closer to reuse.

A more exact word for recycling is often endurvinnsla.

But in environmental contexts, learners may sometimes see slightly broader translations depending on the source and the point being made.

A rough guide is:

• Endurnotkunin ≈ EN-dur-not-kü-nin
• sparar ≈ SPA-rar
• hráefni ≈ HRAU-ev-ni

A few useful pronunciation notes:

• Icelandic stress usually falls on the first syllable
• á sounds roughly like ow in cow
• u is not the English oo sound; it is closer to a front rounded vowel, a bit like German ü
• hr at the start of hráefni can feel unusual for English speakers