Við borðuðum nesti við höfnina áður en ferjan fór.

Because these are actually two different words that just happen to look the same.

• Við at the beginning means we. It is the 1st person plural pronoun.
• við before höfnina is a preposition meaning by, at, near.

So in this sentence:

• Við borðuðum = We ate
• við höfnina = by the harbor

This is very common in Icelandic: one spelling can belong to different parts of speech.

Borðuðum is the past tense of borða (to eat) for við (we).

So:

• ég borðaði = I ate
• þú borðaðir = you ate
• við borðuðum = we ate

The ending -um here marks 1st person plural past. A learner often notices that Icelandic verbs change depending on the subject, and this is a good example of that.

Nesti usually means something like provisions, a packed lunch, or food brought along for a trip.

So it fits well in a sentence about eating before a ferry leaves. It suggests food prepared to take with you, not just food in the abstract.

In context, Við borðuðum nesti is more like:

• We ate our packed lunch
• We had some provisions

rather than simply We ate food.

Here nesti is the direct object of borðuðum, so it is in the accusative case.

The verb borða (to eat) takes an accusative object. In this noun, the accusative form happens to look the same as the nominative, so you do not see a visible change.

That is very common in Icelandic: a noun can be in a different case without changing form in every instance.

Because the preposition við takes the accusative.

So:

• við höfnina = by the harbor

The noun is höfn (harbor, port), and höfnina is the accusative singular definite form: the harbor.

This is something learners need to memorize with prepositions in Icelandic: many prepositions regularly govern a particular case.

In Icelandic, the definite article is usually attached to the end of the noun instead of being a separate word.

So:

• höfn = harbor
• höfnin = the harbor
• höfnina = the harbor (accusative form)

That final -in / -ina is the built-in the.

This is one of the big differences from English. Instead of a separate word like the, Icelandic often adds the article as a suffix.

For the same reason as höfnina: Icelandic usually attaches the definite article to the noun.

• ferja = ferry
• ferjan = the ferry

Here ferjan is the subject of the clause ferjan fór (the ferry left/went), so it is in the nominative singular definite.

Because they come from different kinds of verbs.

• borða is a regular verb, so its past tense is formed in a predictable way: borðaði, borðuðum, etc.
• fara (to go, leave, travel) is a strong/irregular verb, so its past tense changes more dramatically: fór.

So:

• ferjan fór = the ferry left / went

This is similar to English having both regular and irregular verbs:

• walk → walked
• go → went

Áður en means before when it introduces a whole clause.

So:

• áður en ferjan fór = before the ferry left

A useful way to think about it is:

• áður = earlier / before
• en = introducing the following clause

It is a very common structure in Icelandic when one action happens before another.

This is the normal way to say that one event happened before another:

• main clause first: Við borðuðum nesti við höfnina
• time clause after it: áður en ferjan fór

So the sentence is built as:

We ate our packed lunch by the harbor + before the ferry left

You could sometimes rearrange clause order in Icelandic for style or emphasis, but this version is straightforward and natural.

Literally, fara often means go, and fór is went. But in this context, with a ferry, English usually says the ferry left or the ferry departed.

So although the Icelandic verb is the ordinary past tense of fara, the most natural English translation in context is often left.

That is a good reminder that translation is not always word-for-word.

Yes: only the first word is capitalized because it begins the sentence.

So:

• Við at the beginning has a capital V
• við later in the sentence is lowercase because it is not at the start

This can make the two different við forms look even more distinct, but the real difference is grammatical, not just visual.