Ég tek bókina upp úr töskunni.

Because ég means I, and the verb has to match the subject.

The verb here is taka (to take). In the present tense:

• ég tek = I take
• þú tekur = you take
• hann/hún/það tekur = he/she/it takes

So Ég tek is the correct 1st person singular form.

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

Icelandic usually adds the definite article (the) to the end of the noun instead of writing it as a separate word.

So:

• bók = book
• bókin = the book (nominative)
• bókina = the book (accusative)

In this sentence, the book is the direct object of tek, so it appears in the accusative case: bókina.

Because it is the direct object of the verb taka.

In Ég tek bókina..., the thing being taken is the book, so Icelandic puts it in the accusative.

A useful basic rule is:

• subject often in nominative
• direct object often in accusative

So:

• Ég = I (subject)
• tek = take
• bókina = the book (direct object, therefore accusative)

Because úr requires the dative case, and töskunni is the dative singular definite form of taska (bag).

So:

• taska = bag
• taskan = the bag
• töskunni = the bag (dative)

The form changes because of both:

1. the definite ending (the), and
2. the case required by úr

This is due to normal Icelandic noun inflection and vowel change.

The noun is taska (bag), but in some forms the stem changes to tösk-. This is something learners simply have to get used to, because many Icelandic nouns change internally when they decline.

The relevant forms are:

• taska = bag
• tösku = bag (accusative/dative indefinite, depending on context)
• taskan = the bag
• töskunni = the bag (dative definite)

So the ö is part of the noun’s normal pattern.

Here upp úr expresses movement out of something, often with a sense of lifting or drawing something up and out.

In this sentence:

• upp = up
• úr = out of / from inside

Together, they give the idea of taking something up out of the bag.

In natural English, you would usually just say out of the bag, but Icelandic often uses upp to make the movement feel more physical or directional.

Yes, often it could.

Ég tek bókina úr töskunni is also grammatical and would still mean I take the book out of the bag.

Adding upp makes the action feel a little more vivid or physical, as if the book is being lifted out. In many contexts, English would not bother to express this difference clearly, but Icelandic often does.

Because Icelandic often places a particle like upp after the object.

So instead of putting upp immediately after the verb, Icelandic commonly says:

• Ég tek bókina upp úr töskunni

This is very natural.

English does something similar in some cases:

• I pick the book up
• I take the book out

So bókina comes before upp, and then úr töskunni tells you where it is being taken from.

In a way, yes, but here it is especially tied to the direction of movement.

Taka upp can mean several things depending on context, for example:

• pick up
• take up
• record
• bring up (a topic)

But in Ég tek bókina upp úr töskunni, the combination is very literal and physical: take the book up/out of the bag.

So you can think of upp as a particle that helps describe the action, while úr töskunni completes the idea by saying from the bag.

Because úr specifically means out of or from inside, while frá usually means from in a more general sense.

Compare:

• úr töskunni = out of the bag
• frá skólanum = from the school
• frá vini mínum = from my friend

Since the book is being taken from inside the bag, úr is the natural choice.

Yes, both are feminine.

That matters because Icelandic noun endings depend on:

• gender
• number
• case
• whether the noun is definite or indefinite

So the forms in this sentence are shaped partly by the fact that both nouns are feminine:

• bók → bókina
• taska → töskunni

It would be:

Ég tek bók upp úr tösku.

That means something like I take a book out of a bag.

However, in real Icelandic, bare nouns like this can sometimes sound less natural unless the context supports it. Very often you will hear definite forms when specific objects are meant:

• bókina = the book
• töskunni = the bag

So the original sentence sounds like it refers to a specific book and a specific bag.

The dictionary forms are:

• ég = I
• taka = to take
• bók = book
• upp = up
• úr = out of / from inside
• taska = bag

So when learning vocabulary, you would usually store them as:

• taka
• bók (f.)
• taska (f.)

Here is the breakdown:

• Ég — nominative
  The subject of the sentence.

• bókina — accusative
  The direct object, because it is the thing being taken.

• töskunni — dative
  Required by the preposition úr.

So the sentence is a good example of how Icelandic uses different cases for different roles in the sentence.