Á morgun á hún eftir að athuga póstkassann og sækja pakka áður en hún fer í vinnu.

This is a very common Icelandic word-order pattern called V2 (verb second).

If you put a time expression first, like Á morgun (tomorrow), the finite verb usually comes next, and the subject follows it:

Á morgun á hún eftir að...

If the subject came first, you would get:

Hún á eftir að... á morgun.

Both are possible, but the original sentence emphasizes tomorrow by placing it first.

Að eiga eftir að + infinitive is a very common Icelandic construction meaning something like:

• to still have left to do something
• to be yet to do something
• often simply will / is going to do something in context

So:

hún á eftir að athuga póstkassann means roughly she still has to check the mailbox / she will check the mailbox

It is not about possession here, even though eiga normally means to own or to have.

No.

The first Á in Á morgun is part of a fixed time expression meaning tomorrow.

The second á is the verb eiga in the present tense, 3rd person singular:

• ég á
• þú átt
• hún/hann/það á

So in this sentence:

• Á morgun = tomorrow
• á hún eftir að... = she will / she still has left to...

They look the same, but they are different words/functions.

Because the construction is eiga eftir að + infinitive.

So the pattern is:

hún á eftir að athuga...

That að introduces the infinitive verb athuga (to check).

It works much like this structure in English:

• she has left to do
• she is yet to do

Because the two infinitives are coordinated:

að athuga póstkassann og sækja pakka

Here, both athuga and sækja belong to the same að. In English, it is similar to:

to check the mailbox and pick up a package

You do not need to repeat að before the second infinitive.

Because it is a definite direct object in the accusative singular.

The base noun is:

• póstkassi = mailbox

After the verb athuga (check), the object is in the accusative. Since it means the mailbox, not just a mailbox, it also takes the definite ending.

So:

• nominative singular: póstkassi
• accusative singular definite: póstkassann

That is why you see póstkassann.

Because sækja takes a direct object, and the object is in the accusative.

The noun is:

• pakki = package / parcel

Its accusative singular is:

• pakka

So:

• sækja pakka = pick up a package

It is not pakkann because that would mean the package. The sentence uses the indefinite form instead.

One extra detail: pakka can also be an accusative plural form in some contexts, so the exact meaning depends on context and the translation you were given.

Because the sentence treats them differently:

• póstkassann = the mailbox → a specific mailbox
• pakka = a package / package(s) → not specifically identified here

This is very natural. A person usually has one known mailbox, but the package is being mentioned more generally.

So Icelandic is making the same kind of distinction English makes between the mailbox and a package.

Because áður en introduces a new clause, and that clause needs its own subject.

So the structure is:

• main clause: Á morgun á hún eftir að athuga póstkassann og sækja pakka
• subordinate clause: áður en hún fer í vinnu

In English, we also usually keep the subject:

before she goes to work

So the repeated hún is completely normal and necessary here.

Because Icelandic often uses the present tense in subordinate clauses to refer to future events, especially after conjunctions like áður en (before).

So:

áður en hún fer í vinnu literally looks like before she goes to work

Even though it refers to tomorrow, the present tense is the normal choice here.

English often does something very similar:

• Before she goes to work, ... not
• Before she will go to work, ...

So this is not unusual once you get used to it.

Áður en means before.

It introduces a subordinate clause:

• áður en hún fer í vinnu = before she goes to work

A useful way to remember it is that Icelandic often uses en after comparative or linking expressions, and here áður en functions as a set phrase meaning before.

Fara í vinnu is a very common Icelandic expression meaning to go to work.

So:

• hún fer í vinnu = she goes to work

The preposition í is simply the normal idiomatic choice here. Learners often want to translate word-for-word from English, but prepositions do not always match across languages.

So it is best to learn fara í vinnu as a unit.

No, and this is a very important distinction.

• Á morgun = tomorrow
• Í morgun = this morning

They look similar, but they mean very different things. In your sentence, Á morgun clearly means tomorrow.

It breaks down like this:

• Á morgun = time expression, tomorrow
• á hún eftir að = she will / she still has left to
• athuga póstkassann og sækja pakka = the actions, check the mailbox and pick up a package
• áður en hún fer í vinnu = time clause, before she goes to work

So the sentence is basically:

Tomorrow, she will check the mailbox and pick up a package before she goes to work.

This is a very typical Icelandic sentence: time expression first, finite verb second, then the subject, then the rest.