Leikmaðurinn skoraði fyrsta markið.

A very literal breakdown is:

• Leikmaðurinn = the player
• skoraði = scored
• fyrsta = first
• markið = the goal

So the structure is almost literally The player scored the first goal.

Because Icelandic usually puts the definite article directly onto the noun as a suffix.

• leikmaður = player
• leikmaðurinn = the player

Here -inn is the definite article attached to a masculine singular noun in the nominative.

For the same reason: it is a noun with the definite article attached.

• mark = goal
• markið = the goal

mark is a neuter noun, and -ið is the definite ending here. In this sentence it is the direct object, so it is in the accusative, but for many neuter nouns the nominative and accusative singular look the same.

Because Icelandic normally expresses the by attaching it to the noun instead of using a separate word.

So instead of something like English the player, Icelandic often uses:

• leikmaðurinn = player-the

There are separate forms such as hinn / hin / hið, but the suffixed article is the normal everyday pattern in sentences like this.

skoraði is the past tense of the verb skora (to score).

In this sentence it means scored.

More specifically, it is the 3rd person singular past form:

• hann skoraði = he scored
• leikmaðurinn skoraði = the player scored

It is in the nominative case because it is the subject of the sentence — the person doing the action.

Here, leikmaðurinn is the one who scored, so nominative is the expected case.

It is in the accusative case because it is the direct object of skoraði.

The verb skora normally takes a direct object in the accusative:

• skora mark = score a goal

So in this sentence:

• fyrsta markið = the thing that was scored

Because fyrsta has to agree with markið.

mark is:

• neuter
• singular
• here in the accusative

So the adjective/ordinal must match that. Also, because the noun is definite (markið = the goal), the adjective uses the weak form.

That gives:

• fyrsta markið = the first goal

If the noun were masculine nominative singular, you could get a form like fyrsti instead.

It is an ordinal number, but in Icelandic ordinals behave grammatically like adjectives.

So fyrsta comes from fyrstur (first) and changes form to match the noun it describes, just like an adjective would.

That is why it has to agree with markið in gender, number, case, and definiteness.

The dictionary form is fyrstur.

That is the basic masculine nominative singular form. In the sentence, it changes to fyrsta because it is agreeing with a neuter singular noun.

So:

• dictionary form: fyrstur
• sentence form: fyrsta

Yes, but the meaning changes.

• fyrsta markið = the first goal
• fyrsta mark = first goal / a first goal

In this sentence, the definite form markið is natural because it refers to a specific goal — the first one in the match or in the relevant context.

Because that is the normal position in Icelandic.

So Icelandic usually says:

• fyrsta markið = the first goal

not a structure like markið fyrsta in ordinary usage.

The usual order is:

adjective/ordinal + noun

The sentence uses the normal, neutral word order:

• Leikmaðurinn = subject
• skoraði = verb
• fyrsta markið = object

So this is a standard Subject–Verb–Object sentence.

However, Icelandic is also a verb-second language in main clauses. That means other elements can be moved to the front for emphasis, but the finite verb usually stays in the second position. For example:

• Í leiknum skoraði leikmaðurinn fyrsta markið = In the match, the player scored the first goal

You can also front the object for special emphasis, though that is more marked and needs the right context.