Á hátíðinni í fyrra vorum við úti allan tímann, en í ár fórum við inn.

Á hátíðinni means at the festival.

Two useful things are happening here:

1. The preposition

   • Icelandic often uses á with events:
     • á hátíð = at a festival
     • á tónleikum = at a concert
     • á fundi = at a meeting
   • So even though English says at, Icelandic often says á in these contexts.

2. The case

   • á can take different cases depending on meaning.
   • With location or being somewhere, it usually takes the dative.
   • Here we are talking about being at the festival, not moving onto it, so dative is used.

So:

• hátíð = festival
• hátíðinni = the festival (dative singular, with the suffixed definite article)

The -inni ending shows the definite form in the dative singular.

Í fyrra is a very common fixed expression meaning last year.

Even though there is no noun written after fyrra, the meaning is understood. Learners should treat í fyrra as an idiomatic time expression rather than trying to translate each part too mechanically.

A helpful comparison:

• í ár = this year
• í fyrra = last year

So in this sentence, á hátíðinni í fyrra means at the festival last year.

This is because Icelandic is a verb-second (V2) language in main clauses.

That means the finite verb usually comes in the second position. If something other than the subject comes first, the verb still stays second, and the subject comes after it.

Here is the pattern:

• Á hátíðinni í fyrra
  • vorum
    • við
• Í ár
  • fórum
    • við

So the sentence begins with a time/place phrase, and that causes inversion:

• Á hátíðinni í fyrra vorum við...
• ...en í ár fórum við inn.

If the subject came first, you could say:

• Við vorum úti allan tímann á hátíðinni í fyrra...

That would also be grammatical, but it would be structured differently.

They come from two different verbs:

• vorum = past tense of vera (to be)
• fórum = past tense of fara (to go)

So:

• vorum við úti = we were outside
• fórum við inn = we went inside

This contrast is important:

• vera describes a state/location
• fara describes movement

That is why the first clause describes where they were, while the second clause describes a change of place.

Because the two clauses express different kinds of meaning:

• úti = outside / outdoors as a location
• inn = in / inside / inward as direction or movement

In the first clause:

• vorum við úti = we were outside
• This is a location/state.

In the second clause:

• fórum við inn = we went inside
• This is movement toward the inside.

A very useful contrast is:

• úti = outside
• inni = inside, when talking about being inside
• inn = inward / inside, when talking about going in

So compare:

• Við vorum inni. = We were inside.
• Við fórum inn. = We went in.

Allan tímann means the whole time or all the time.

This is an example of the accusative of duration, which is very common in Icelandic. When you say how long something lasted, Icelandic often uses the accusative case.

Here:

• allur tíminn = the whole time (nominative)
• allan tímann = the whole time (accusative)

So:

• vorum við úti allan tímann = we were outside the whole time

The phrase is masculine singular accusative because tími is a masculine noun.

En means but here.

It connects the two clauses and shows a contrast:

• last year: we were outside the whole time
• this year: we went inside

So en marks the change between the two situations.

Yes—í ár is a very common expression, and it is best learned as a chunk meaning this year.

So:

• í ár = this year
• í fyrra = last year

These are extremely frequent time expressions in Icelandic, and learners will see them often.

In this sentence, en í ár fórum við inn means:

• but this year we went inside

So even though English uses this, Icelandic uses the fixed phrase í ár.

You can think of it both ways, but grammatically it is helpful to see it as:

• á hátíðinni = at the festival
• í fyrra = last year

Together they form a larger phrase meaning:

• at the festival last year

So í fyrra is adding time information to á hátíðinni.

A good way to parse the sentence is:

• Á hátíðinni í fyrra = At the festival last year
• vorum við úti allan tímann = we were outside the whole time
• en í ár = but this year
• fórum við inn = we went inside

That breakdown often makes the sentence much easier to understand.