Skyndihjálpin mun koma í veg fyrir meira heilsutjón.

Skyndihjálp means first aid. The form Skyndihjálpin is the definite form, meaning the first aid.

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

• skyndihjálp = first aid
• skyndihjálpin = the first aid

The noun is feminine, and -in is the nominative singular definite ending here.

Depending on context, Icelandic may use the definite form where English would sometimes still just say first aid.

Mun is the 3rd person singular form of munu, which is often used to express the future, similar to will in English.

So:

• mun koma = will come
• but in this sentence, because of the idiom, it means will prevent

A useful point: Icelandic does not always need a special future marker. Very often the present tense can refer to the future too. Using mun makes the future meaning more explicit or predictive.

Because it follows the finite verb mun.

This works very much like English:

• will come
• mun koma

Here:

• mun = the finite verb
• koma = the infinitive

So the structure is normal for Icelandic after munu.

Literally, the words do suggest something like that, but you should learn koma í veg fyrir as a fixed expression meaning to prevent.

So in this sentence:

• Skyndihjálpin mun koma í veg fyrir meira heilsutjón
  = The first aid will prevent further/more health damage

This is a very common kind of thing in Icelandic: a phrase may be built from familiar words, but the whole expression has to be learned as one unit.

Because it is part of the fixed expression koma í veg fyrir.

On its own, fyrir can have several meanings, such as for, before, or other uses depending on context and case. But here you should not interpret it separately in a literal way. In this sentence, fyrir is simply part of the verb phrase meaning prevent.

So it is best to remember:

• koma í veg fyrir e-ð = to prevent something

Because heilsutjón is a neuter singular noun, and meiri changes form to agree with it.

The comparative adjective meiri means more or greater, and its form changes by gender and number. With a neuter singular noun, the form is meira.

Compare:

• meiri skaði = more damage/harm (skaði is masculine)
• meiri hætta = greater danger (hætta is feminine)
• meira tjón = more damage (tjón is neuter)

Since heilsutjón is neuter, meira heilsutjón is correct.

Because meira and fleira are not used in the same way.

• meira = more in amount or degree
• fleira = more in number

Heilsutjón means damage to health, which is treated as an uncountable or mass-type noun here. So Icelandic uses meira, not fleira.

A similar English distinction is:

• more damage
  not
• more damages in this sense

It is a compound noun, which is extremely common in Icelandic.

It is made from:

• heilsa = health
• tjón = damage, loss, harm

Together, heilsutjón means something like health damage or harm to health.

In Icelandic compounds, the last part usually determines the grammatical gender and inflection. Since tjón is neuter, heilsutjón is also neuter.

It is the object of the expression koma í veg fyrir, so it is in the case required by that expression, normally the accusative.

In this particular sentence, though, heilsutjón is a neuter singular noun, and its nominative and accusative forms are the same, so you do not see a visible change in the noun itself.

The adjective form meira also fits the neuter singular form needed here.

This is standard Icelandic main-clause word order.

Icelandic is a V2 language, which means the finite verb usually comes in the second position in a main clause. Here:

1. Skyndihjálpin = first element
2. mun = finite verb in second position

Then the infinitive koma comes later.

So the structure is perfectly normal:

• Skyndihjálpin mun koma í veg fyrir...

If another element came first, the finite verb would still usually stay second:

• Með skjótum viðbrögðum mun skyndihjálpin koma í veg fyrir meira heilsutjón.

Yes. Skyndihjálp is normally treated as a singular noun, just like first aid in English.

It refers to the general act or practice of giving immediate medical help, not to separate countable items. So singular is the natural form here.

That is why the verb is also singular:

• Skyndihjálpin mun...
  not
• Skyndihjálpin munu...