Ég les bók í rúminu án þess að kveikja á lampanum.

It can mean either one.

In Icelandic, the simple present often covers both:

• I read a book
• I am reading a book

So Ég les bók can be understood as either a general present or an ongoing action, depending on context.

It is the direct object, so it is in the accusative.

The verb lesa usually takes an accusative object:

• lesa bók = to read a book

In this particular noun, the nominative singular and accusative singular look the same:

• nominative: bók
• accusative: bók

So even though it is accusative here, you do not see a different form.

Because bók means a book, while bókina means the book.

Icelandic does not have a separate word like English a/an. A bare noun often gives the indefinite meaning:

• bók = a book
• bókina = the book

So Ég les bók is naturally I am reading a book / I read a book.

Because this sentence describes location, not movement.

With í:

• dative = being in something
• accusative = going into something

So:

• í rúminu = in the bed / in bed
• í rúmið = into the bed

Here the person is already in bed while reading, so Icelandic uses the dative: rúminu.

It means without followed by an action, here:

• án þess að kveikja á lampanum = without turning on the lamp

This is a very common Icelandic pattern.

A useful way to think of it is:

• án þess að + infinitive

Examples:

• án þess að tala = without speaking
• án þess að borða = without eating

So in your sentence, it introduces something that does not happen while the main action happens.

Because án þess að is basically a fixed expression in Icelandic.

You do not need to translate þess word-for-word every time. For learners, it is best to memorize the whole pattern:

• án þess að = without doing / without the fact that

Historically and grammatically, þess is connected to the pronoun það, but in practice the whole chunk functions together. Native English speakers often find it strange at first because English just says without.

Because kveikja á is the normal Icelandic expression for turn on or switch on something.

So:

• kveikja á lampanum = turn on the lamp
• kveikja á sjónvarpinu = turn on the television

This is an idiomatic verb + preposition combination, so it should be learned as a unit:

• kveikja á + dative

English speakers often want to translate directly from turn on, but in Icelandic the preposition á is part of the expression.

Because lampi is in the dative singular definite form here.

That happens because kveikja á takes the dative:

• lampi = a lamp
• lampa = a lamp (dative singular, indefinite)
• lampanum = the lamp (dative singular, definite)

So the ending -num here reflects both:

• dative case
• definite article (the)

This is very typical in Icelandic, where the is usually attached to the noun as an ending.

It is understood to be the same subject as in the main clause: ég.

So the sentence means that I am reading a book in bed without turning on the lamp.

In other words, the person doing les is also the person not doing kveikja á lampanum.

That is one reason the infinitive works so naturally here.

Yes, to some extent.

The neutral order here is:

• Ég les bók í rúminu án þess að kveikja á lampanum.

But Icelandic allows some movement for emphasis, especially at the beginning of the sentence. For example:

• Í rúminu les ég bók án þess að kveikja á lampanum.

That puts more focus on in bed.

A very important rule is that in a main clause, Icelandic usually keeps the finite verb in the second position. So if another element comes first, the verb still stays second:

• Í rúminu
  • les
    • ég ...

That is a major difference from English word order.