Við förum inn um innganginn og finnum útganginn seinna.

Við means we.

It is the 1st person plural subject pronoun, so it tells you that the speakers are including themselves: we go in ... and find ... later.

Be careful not to confuse við with the preposition við, which can also mean things like by, with, or against in other contexts. In this sentence, it is clearly the pronoun we because it comes before the verb.

Because förum is the form of the verb that matches við (we).

The dictionary form is fara = to go, but Icelandic verbs change depending on the subject.

Here are the present tense forms of fara:

• ég fer = I go
• þú ferð = you go
• hann/hún/það fer = he/she/it goes
• við förum = we go
• þið farið = you all go
• þeir/þær/þau fara = they go

So við förum = we go.

Because Icelandic often leaves out the subject in the second part of a compound sentence when it is the same as before.

So:

• Við förum inn um innganginn og finnum útganginn seinna.

means literally:

• We go in through the entrance and find the exit later.

You could say og við finnum útganginn seinna, but it is often unnecessary because við is already understood.

They work together, but they do different jobs.

• inn means in / inside / inward
• um is a preposition that here means something like through

So inn um innganginn means in through the entrance.

A good way to feel the structure is:

• fara inn = to go in
• fara inn um X = to go in through X

So inn gives the direction inward, and um innganginn tells you the route: through the entrance.

That -inn is the definite article, attached to the noun.

So:

• inngangur = an entrance
• innganginn = the entrance
• útgangur = an exit
• útganginn = the exit

Unlike English, Icelandic usually puts the at the end of the noun instead of using a separate word.

So:

• um innganginn = through the entrance
• finnum útganginn = find the exit

This happens because the noun changes form by case.

The basic dictionary forms are:

• inngangur
• útgangur

But in this sentence both nouns are in the accusative singular definite form:

• innganginn
• útganginn

Many masculine nouns ending in -ur change like this:

• nominative indefinite: inngangur
• accusative indefinite: inngang
• accusative definite: innganginn

and similarly:

• útgangur → útgang → útganginn

So the ending changes because Icelandic marks grammatical function with case endings.

For two different grammar reasons:

1. um often takes the accusative, so:

   • um innganginn

2. finna takes a direct object in the accusative, so:

   • finna útganginn

So although both nouns are accusative, they are accusative for different reasons:

• one after a preposition,
• one as the object of a verb.

Yes. Finna means to find.

So:

• finnum útganginn = we find the exit

Depending on context, English might sometimes phrase this more naturally as figure out where the exit is or find our way to the exit, but grammatically the Icelandic is simply find the exit.

Seinna means later.

It is placed at the end because Icelandic word order is often flexible, and adverbs like this commonly come late in the clause.

So:

• finnum útganginn seinna = find the exit later

That sounds very natural.

You may also meet síðar, which can also mean later. In many contexts they are close in meaning, though seinna is very common in everyday speech.

The sentence has a very natural Icelandic word order:

• Við förum = subject + verb
• inn um innganginn = directional phrase
• og finnum útganginn seinna = second verb phrase

A very literal structure would be:

• We go in through the entrance and find the exit later.

Icelandic does allow some word order variation, but this version is straightforward and idiomatic.

It has two coordinated parts joined by og = and:

1. Við förum inn um innganginn

   • við = we
   • förum = go
   • inn = in
   • um innganginn = through the entrance

2. (við) finnum útganginn seinna

   • (við) = we, understood
   • finnum = find
   • útganginn = the exit
   • seinna = later

So the logic is:

• We go in through the entrance, and we find the exit later.

Yes. They are a useful pair:

• inngangur

  • inn = in
  • gangur = passage / going / corridor-related noun
  • together: entrance

• útgangur

  • út = out
  • gangur
  • together: exit

So they are built in parallel:

• in-going / entrance
• out-going / exit

This kind of word-building is very common in Icelandic and can help you guess meanings.

A few common pronunciation points:

• við: the ð is like a soft th in this
• förum: ö is not like English o; it is closer to the vowel in some pronunciations of French peur or German hören
• innganginn: notice the double nn and the stress on the first syllable
• útganginn: ú is a long oo-like sound
• seinna: the ei is pronounced like ay in say, roughly speaking

Also, Icelandic almost always stresses the first syllable of the word:

• VIÐ
• FÖ-rum
• INN-ganginn
• ÚT-ganginn
• SEIN-na

Not naturally in the same meaning.

If you want to say go in through the entrance, um is the important preposition:

• fara inn um innganginn

Without um, the meaning changes or becomes less natural. The preposition tells you the path or opening you go through.

So inn um innganginn is the normal way to express in through the entrance.