Við sættumst loksins eftir langan dag og borðuðum kvöldmat saman.

Here við means we.

That can be confusing for English speakers because it looks a bit like it might mean with, but Icelandic við is the pronoun we. The preposition with is usually með.

So:

• Við sættumst = We made up / We reconciled
• með vini mínum = with my friend

Sættumst is the past tense, 1st person plural form of að sættast.

So the basic dictionary form is:

• að sættast = to reconcile, make up, become friends again

In this sentence:

• við sættumst = we reconciled / we made up

This is a very common kind of question because the form sættumst looks quite different from the dictionary form sættast.

The -st ending marks a middle voice form, which is very common in Icelandic.

In practice, middle voice verbs often have meanings that are:

• reflexive
• reciprocal
• passive-like
• or just idiomatic

Here, að sættast has a reciprocal sense:
to make up with each other / to reconcile

So við sættumst does not mean that we reconciled something; it means we ourselves became reconciled.

A useful comparison:

• að sætta = to reconcile, settle
• að sættast = to reconcile / make up

Sometimes a related expression does, yes.

There is an important difference between:

• að sættast = to make up, reconcile
• að sætta sig við e-ð = to accept something, come to terms with something

So in your sentence, Við sættumst on its own is understood as we made up / reconciled, not we accepted.

Because Icelandic main clauses usually follow a verb-second pattern.

In a normal statement, the finite verb tends to come early in the clause, and adverbs like loksins often come after it.

So:

• Við sættumst loksins = We finally made up

This word order is very natural in Icelandic.

You can move things around for emphasis, but the sentence as given is the ordinary, idiomatic order.

Because here eftir takes the accusative in this time expression, so both the adjective and noun appear in the masculine singular accusative:

• langan = accusative masculine singular of langur
• dag = accusative singular of dagur

So:

• eftir langan dag = after a long day

This is a very common thing to notice in Icelandic: the preposition controls the case, and the adjective has to agree with the noun.

Because it has to agree with dag in:

• gender: masculine
• number: singular
• case: accusative

The noun is:

• dagur = a day

But after eftir here, it becomes:

• dag

And the adjective langur changes to match:

• langan dag = a long day in the accusative

So the ending -an is not random; it is showing grammatical agreement.

Borðuðum is the past tense, 1st person plural of að borða (to eat).

So:

• að borða = to eat
• við borðuðum = we ate

In the sentence:

• og borðuðum kvöldmat saman = and ate dinner together

The ending -uðum is a common past-tense plural ending for many weak verbs.

Because the subject is already understood.

Just like in English, if the same subject continues after and, Icelandic often leaves it out:

• Við sættumst ... og borðuðum ...
• literally: We made up ... and ate ...

You could repeat við, but it is usually unnecessary here.

Also, the verb form borðuðum already shows we, so the meaning is clear.

Because kvöldmat is the accusative singular form of kvöldmatur.

Dictionary form:

• kvöldmatur = dinner / evening meal

But as the direct object of borðuðum, it appears in the accusative:

• borðuðum kvöldmat = ate dinner

This is another very common Icelandic pattern: nouns change form depending on their grammatical role.

Because Icelandic often leaves out the article when talking about meals in a general sense, much like English.

So:

• borða kvöldmat = eat dinner

This is natural and idiomatic. You do not need the unless you mean a specific dinner in context.

Saman means together.

So:

• borðuðum kvöldmat saman = ate dinner together

The sentence would still make sense without saman, but adding it emphasizes that they were together after reconciling. It helps complete the emotional picture of the sentence.

Yes. Both sættumst and borðuðum are in the past tense, and both refer to we.

So the structure is:

• Við sættumst = We made up
• og borðuðum = and ate

This makes the sentence feel like a simple sequence of past events:

1. they reconciled
2. then they ate dinner together

Yes. Og is the ordinary Icelandic word for and.

Here it simply joins two past-tense actions:

• sættumst
• borðuðum

So the sentence is built very straightforwardly:

• Við sættumst loksins
• eftir langan dag
• og borðuðum kvöldmat saman

A helpful breakdown is:

• Við = we
• sættumst = made up / reconciled
• loksins = finally
• eftir langan dag = after a long day
• og = and
• borðuðum kvöldmat saman = ate dinner together

So grammatically, it is:

• subject
• first verb phrase
• time phrase
• coordinated second verb phrase

That makes it a good example of a very natural Icelandic past-tense sentence with two linked actions.