Hún les lokaorðin upphátt um leið og ég loka fartölvunni.

It is an idiomatic time expression meaning as, just as, or at the same time as.

So:

• Hún les lokaorðin upphátt = she reads the final words aloud
• um leið og ég loka fartölvunni = as I close the laptop

Even though um, leið, and og each have their own basic meanings, you should learn um leið og as a set phrase.

Because Icelandic very often makes compound nouns where English would use two words.

• loka = closing / final
• orð = word

Together:

• lokaorð = closing word / final word
• lokaorðin = the closing words / the final words

This is very normal in Icelandic. English often separates words where Icelandic combines them.

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

In this sentence:

• lokaorðin = the final words
• fartölvunni = the laptop

So instead of using a separate word like English the, Icelandic often builds that meaning into the noun itself.

Here lokaorðin is the direct object of les and is therefore in the accusative.

The verb lesa normally takes an accusative object:

• lesa bók = read a book
• lesa lokaorðin = read the final words

Why does it look like lokaorðin and not something obviously accusative? Because with many neuter plural nouns, the nominative and accusative forms are the same.

So:

• nominative plural definite: lokaorðin
• accusative plural definite: lokaorðin

Same form, different grammatical role.

Because the verb loka meaning to close takes the dative case in Icelandic.

That is something English speakers often have to get used to: Icelandic verbs do not all take the same kind of object.

So:

• ég loka fartölvunni = I close the laptop

Here:

• fartölva = laptop
• fartölvu = dative singular stem
• fartölvunni = the laptop in dative singular

A useful thing to memorize is:

• lesa eitthvað = read something, with accusative
• loka einhverju = close something, with dative

Because they are different verbs with different conjugation patterns.

les

This comes from lesa = to read.
It is not a regular -a verb in the present tense.

Present tense of lesa:

• ég les
• þú lest
• hann/hún/það les
• við lesum
• þið lesið
• þeir/þær/þau lesa

So hún les is exactly what you expect.

loka

This is a more regular verb:

• ég loka
• þú lokar
• hann/hún/það lokar

So ég loka is also exactly right.

Upphátt means aloud or out loud.

So:

• Hún les lokaorðin upphátt = She reads the final words aloud

It is an adverb, not an adjective. It describes how she reads.

It is commonly used with verbs like:

• lesa upphátt = read aloud
• segja upphátt = say aloud

Its position here is perfectly natural.

Because Icelandic often uses the simple present where English would use the present progressive.

So Icelandic:

• Hún les ... ég loka ...

can naturally correspond to English:

• She is reading ... as I am closing ...

If you want to emphasize that an action is ongoing, Icelandic can also use vera að + infinitive:

• Hún er að lesa lokaorðin upphátt
• ég er að loka fartölvunni

But in a sentence like this, the plain present is very normal and idiomatic.

The sentence has:

1. a main clause
   
   • Hún les lokaorðin upphátt
2. a time clause introduced by um leið og
   
   • ég loka fartölvunni

So the structure is:

• [Main clause] + [time clause]

This order is natural, but you can also put the time clause first:

• Um leið og ég loka fartölvunni les hún lokaorðin upphátt.

When you do that, Icelandic keeps its usual verb-second pattern in the main clause, so les comes right after the fronted clause.

Not really. In this sentence, og is part of the fixed expression um leið og.

So you should not interpret it simply as:

• um leið = something
• og = and

Instead, take the whole phrase together:

• um leið og = as / just as / at the same time as

That is the most useful way to understand and remember it.