Bókin var liggjandi á stólnum alla nóttina.

Bókin means the book.

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

• bók = book
• bókin = the book

In this sentence, bókin is in the nominative singular, because it is the subject of the sentence.

• bók = an indefinite form
• bókin = the definite form

So Bókin var... means The book was...

Var is the past singular form of vera (to be).

Since bókin is singular, the verb is also singular:

• ég var = I was
• hann/hún/það var = he/she/it was

So:

• Bókin var... = The book was...

If the subject were plural, you would expect voru instead:

• Bækurnar voru... = The books were...

Liggjandi is the present participle of liggja, which means to lie or to be lying.

So:

• liggja = to lie
• liggjandi = lying

In this sentence, var liggjandi gives the idea that the book was in a lying position.

A useful thing to know is that Icelandic -andi participles are often indeclinable, so liggjandi does not change form for gender, number, or case.

It is similar, but not exactly the same.

English uses be + -ing very freely:

• The book was lying on the chair

Icelandic can use vera + -andi, but it is not a general, all-purpose progressive in the same way English is. It often sounds more descriptive or state-focused.

So var liggjandi suggests that the book was there in a lying position over that period of time.

It is close in meaning to English was lying, but learners should not assume that Icelandic always translates English progressives with vera + -andi.

Yes. That is a very natural alternative.

• Bókin lá á stólnum alla nóttina.

Here lá is the past tense of liggja.

The difference is roughly this:

• lá = a simple past statement: the book lay / was lying
• var liggjandi = more descriptive, emphasizing the state or posture

In many contexts, lá is the more straightforward way to say it. Var liggjandi is still understandable and can add a slightly more vivid or durational feel.

Icelandic often uses posture verbs to describe how something is positioned.

Common ones include:

• liggja = lie
• sitja = sit
• standa = stand

This is used not only for people, but also for objects.

So for an object like a book, Icelandic may naturally describe it as lying somewhere if it is resting flat. English can do this too, but English often prefers a simpler sentence like The book was on the chair.

So this sentence reflects a very common Icelandic way of describing position.

Because this sentence describes location, not motion toward something.

With á:

• á + dative = on something, in a static location
• á + accusative = onto something, movement toward a surface

So:

• á stólnum = on the chair (already there)
• á stólinn = onto the chair (movement onto it)

Since the book was already on the chair, Icelandic uses the dative:

• stólnum = dative singular definite of stóll (chair)

It marks both case and definiteness.

The base noun is:

• stóll = chair

Here it appears as:

• stólnum = the chair in the dative singular

That form is used because:

1. á takes the dative for static location
2. the noun is definite: the chair

So á stólnum literally means something like on-the-chair.

This is an example of the accusative of duration.

Icelandic often uses the accusative case to express how long something lasted.

So:

• alla nóttina = all night
• literally: the whole night

Breaking it down:

• nótt = night
• nóttina = the night
• alla = all / whole, agreeing with nóttina

Even though English does not show case here, Icelandic does. The accusative is used because the phrase answers the question for how long?

Yes.

Alla must match nóttina in the relevant grammatical features. Here the phrase is feminine singular accusative.

• nótt is a feminine noun
• nóttina is feminine singular accusative definite
• alla matches that form

So the phrase works as a unit:

• alla nóttina = all night

This kind of agreement is very important in Icelandic: adjectives and words like allur often change form to match the noun they belong to.

This sentence has a normal, neutral word order:

• Bókin var liggjandi á stólnum alla nóttina.

But Icelandic word order is fairly flexible, especially if you want to emphasize time or place.

For example, you could also say:

• Alla nóttina var bókin liggjandi á stólnum.
• Á stólnum var bókin liggjandi alla nóttina.

These have slightly different emphasis, but the basic meaning stays similar.

One important rule in Icelandic is the verb-second tendency in main clauses: when another element comes first, the finite verb often comes next.

So:

• Bókin var...
• Alla nóttina var...
• Á stólnum var...

That is a useful pattern to notice early.