Hún sendi stutta skýrslu eftir fundinn, svo allir vissu hvað hafði verið ákveðið.

Because sendi takes a direct object, and that object is in the accusative case.

• Dictionary form: stuttur = short
• Dictionary form: skýrsla = report
• Here: stutta skýrslu = short report

Both the adjective and the noun have to match in:

• case: accusative
• gender: feminine
• number: singular

So:

• skýrsla → skýrslu
• stuttur → stutta

This is a very common pattern in Icelandic: adjectives change form to agree with the noun they describe.

The ending -inn is the definite article, attached to the noun itself. Icelandic usually adds the to the end of the noun instead of using a separate word.

So:

• fundur = meeting
• fundinn = the meeting

In this sentence, eftir fundinn means after the meeting, not just after a meeting.

Also, because eftir here takes the accusative, fundur changes to fundinn rather than staying in its basic form.

The preposition eftir can govern different cases depending on meaning, but when it means after in a time sense, it usually takes the accusative.

So here:

• eftir fundinn = after the meeting

This is a standard time expression. Icelandic prepositions often require specific cases, so learners usually need to memorize them together with their meanings.

Here svo means something like so, so that, or with the result that.

In this sentence, it connects the two parts:

• She sent a short report after the meeting,
• so everyone knew what had been decided.

It is showing a result or consequence.

Depending on context, svo can also mean things like:

• then
• thus
• very/so in other kinds of sentences

But here it is clearly a conjunction meaning so.

Both word order and clause type matter here.

After svo, this part behaves like a subordinate/result clause, and Icelandic often keeps the subject before the verb there:

• svo allir vissu

That is different from the classic verb-second word order you often see in main clauses.

A useful beginner-level way to think about it is:

• main clause: verb often comes early, usually in second position
• subordinate/dependent clause: subject often comes before the verb

So svo allir vissu is natural here.

Because vita is an irregular verb.

Its forms are:

• infinitive: vita = to know
• present: veit = know / knows
• past singular: vissi = knew
• past plural: vissu = knew

Since the subject is allir = everyone / all, the verb is in the plural past:

• allir vissu = everyone knew

Even though English often uses singular everyone, Icelandic allir is grammatically plural.

Because allir literally means all or all people, and it is grammatically plural.

So Icelandic says:

• allir vissu = all knew / everyone knew

Even when the English translation uses singular everyone, Icelandic may use a plural form if the actual Icelandic word is plural.

This is a good reminder not to map English grammar directly onto Icelandic grammar.

This is a past perfect passive construction.

Breakdown:

• hafði = had
• verið = been
• ákveðið = decided

So:

• hafði verið ákveðið = had been decided

And with hvað:

• hvað hafði verið ákveðið = what had been decided

Why past perfect? Because the deciding happened before the moment when everyone knew. The sentence is talking about one past action that was already completed before another past moment.

Ákveðið is the past participle of ákveða = to decide, and here it appears in the passive construction verða/vera + past participle.

It is in the neuter singular form because the clause is being used in an impersonal/general way:

• það hafði verið ákveðið = it had been decided

Even though það is not stated, the construction works like an impersonal it had been decided, so the neuter singular participle is used.

This is very common in Icelandic passive and impersonal expressions.

Yes, but the meaning would change slightly.

• hvað var ákveðið = what was decided
• hvað hafði verið ákveðið = what had been decided

The version in your sentence, hafði verið ákveðið, places the deciding clearly before the time when everyone knew. It adds an extra layer of past time.

So:

• vissu hvað var ákveðið = everyone knew what was decided
• vissu hvað hafði verið ákveðið = everyone knew what had been decided

The second one is a bit more explicitly retrospective.

Hvað means what, and here it introduces an embedded question or indirect question:

• hvað hafði verið ákveðið = what had been decided

This is not a direct question like Hvað hafði verið ákveðið? Instead, it is part of a larger sentence:

• allir vissu hvað hafði verið ákveðið = everyone knew what had been decided

English does the same thing:

• direct question: What had been decided?
• embedded question: They knew what had been decided.

Yes, it is normal and helpful here because the sentence contains two clauses:

• Hún sendi stutta skýrslu eftir fundinn
• svo allir vissu hvað hafði verið ákveðið

The comma marks the boundary between them and makes the structure easier to read.

Icelandic punctuation is often a bit more clause-based than English learners expect, so commas like this are very common.

Yes. Icelandic word order is flexible, especially with adverbials like time expressions.

For example, you could also say:

• Hún sendi eftir fundinn stutta skýrslu, svo allir vissu hvað hafði verið ákveðið.

That is still understandable, though Hún sendi stutta skýrslu eftir fundinn sounds very natural and straightforward.

In general, Icelandic allows movement of phrases for emphasis, rhythm, or style, but not every order sounds equally neutral. The original sentence has a clear, natural default order.