Um leið og ég kem á skrifstofuna, opna ég fartölvuna mína.

Um leið og is a very common Icelandic expression meaning as soon as, just when, or the moment that.

So in this sentence, it introduces a time clause:

• Um leið og ég kem á skrifstofuna = As soon as I get to the office

It is not usually translated word-for-word in a natural way. Literally, it is something like at the same moment as.

A learner might also compare it with:

• þegar = when
• um leið og = as soon as / right when

So um leið og often feels a bit more immediate.

Kem is the correct conjugated form of the verb koma (to come) for ég (I) in the present tense.

The verb koma is conjugated like this in the present:

• ég kem = I come
• þú kemur = you come
• hann/hún/það kemur = he/she/it comes
• við komum = we come
• þið komið = you all come
• þeir/þær/þau koma = they come

So because the subject is ég, you need kem.

This is about case and the difference between movement toward a place and location in a place.

With many Icelandic prepositions, including á, the case changes depending on meaning:

• accusative = movement to a place
• dative = being in/on/at a place

Here, ég kem á skrifstofuna means I come to the office, so there is movement toward the office. That is why you get:

• á skrifstofuna — accusative

If you were talking about being at the office, you would use dative:

• ég er á skrifstofunni = I am at the office

So the contrast is:

• á skrifstofuna = to the office
• á skrifstofunni = at the office

The -na shows that the noun is both:

1. definite = the office
2. in the accusative singular

The basic noun is:

• skrifstofa = office

Its definite accusative singular form is:

• skrifstofuna = the office

So in this sentence, á skrifstofuna means to the office, not just to an office.

This is because Icelandic follows a verb-second pattern in main clauses.

When the sentence begins with something other than the subject, the finite verb usually comes next. Here, the whole time clause comes first:

• Um leið og ég kem á skrifstofuna

After that, the main clause begins, and Icelandic puts the verb first:

• opna ég fartölvuna mína

So the structure is:

• [subordinate clause], [verb] [subject] ...

This is very common in Icelandic.

Compare:

• Ég opna fartölvuna mína. = I open my laptop.
• Um leið og ég kem á skrifstofuna, opna ég fartölvuna mína. = As soon as I get to the office, I open my laptop.

In English, we do not usually notice this kind of inversion, but in Icelandic it is an important rule.

Here, opna is the present tense form of the verb að opna (to open) for ég.

This verb is regular in the present tense:

• ég opna = I open
• þú opnar = you open
• hann/hún/það opnar = he/she/it opens

So even though the word order is opna ég, it still means I open.

The verb form itself has not changed; only the word order has.

Because fartölvuna is the definite accusative singular form of fartölva (laptop).

You need the accusative here because fartölvuna mína is the direct object of opna:

• opna hvað? = open what?
• fartölvuna mína = my laptop

Here are the relevant forms:

• fartölva = a laptop
• fartölvan = the laptop
• fartölvuna = the laptop (accusative)

So:

• opna fartölvuna mína = open my laptop

In Icelandic, possessive words like minn / mín / mitt often come after the noun, especially when the noun is definite.

So this pattern is very normal:

• fartölvuna mína = my laptop
• literally: the laptop my

This is one of the ways Icelandic differs from English.

The possessive must also agree with the noun in gender, number, and case. Since fartölvuna is:

• feminine
• singular
• accusative

the possessive becomes:

• mína

Yes, but it is not the same in tone or usage.

The most neutral and common way to say my laptop in a sentence like this is:

• fartölvuna mína

Using the possessive before the noun, like:

• mín fartölva

is possible, but it often sounds more emphatic, contrastive, or stylistically different.

So for ordinary everyday usage, especially with a definite object, fartölvuna mína is the form learners should get used to first.

The comma is normal and helpful here because the sentence begins with a subordinate time clause:

• Um leið og ég kem á skrifstofuna, ...

Then the main clause follows:

• ... opna ég fartölvuna mína.

In written Icelandic, a comma is commonly used to separate that opening clause from the main clause.

So yes, the comma is natural and expected here.

Yes, you could, but the meaning would change slightly.

• Þegar ég kem á skrifstofuna, opna ég fartölvuna mína.
  = When I get to the office, I open my laptop.

• Um leið og ég kem á skrifstofuna, opna ég fartölvuna mína.
  = As soon as I get to the office, I open my laptop.

The version with um leið og emphasizes that the second action happens immediately after the first.

So both are grammatical, but um leið og is more precise if you want the idea of right away.

This is a very good question, because Icelandic prepositions do not always match English ones directly.

The preposition á often corresponds to on, but in many expressions it also means at or to, depending on context.

With places like skrifstofa (office), Icelandic commonly uses:

• á skrifstofunni = at the office
• á skrifstofuna = to the office

So even if it looks strange from an English point of view, it is simply the normal Icelandic choice. You should learn it as a fixed pattern:

• koma á skrifstofuna = come to the office

Grammatically, both verbs are in the present tense, but Icelandic present tense can be used in ways that English might express differently.

This sentence could mean something like:

• a habitual action: whenever I get to the office, I open my laptop
• a planned or vivid future action, depending on context

Without extra context, many learners will understand it as a regular routine:

• As soon as I get to the office, I open my laptop.

So even though it is present tense, the real-time meaning depends on the situation.