Við setjum kubbana og litabókina á borðið eftir morgunmat.

Setja is the infinitive, meaning to put / to place.
In the sentence, the verb has to agree with við (we), so it becomes setjum, which is the 1st person plural present tense.

So:

• setja = to put
• við setjum = we put / we are putting

In context, this can describe either a general action or what we are doing now, depending on the situation.

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

In this sentence:

• kubbana = the blocks
• litabókina = the coloring book
• borðið = the table

So Icelandic often does with endings what English does with a separate word like the.

Because the nouns are different in gender and number, and Icelandic endings change accordingly.

Here:

• kubbana comes from kubbur and is masculine plural definite
• litabókina comes from litabók and is feminine singular definite

They are both direct objects of setjum, so they are in the case required by that verb, but they still take different endings because they belong to different noun patterns.

Dictionary forms are usually nominative singular:

• kubbur
• litabók

But in the sentence, these words are direct objects, and Icelandic usually changes nouns according to their grammatical role. After setja, the direct object is typically in the accusative.

So the nouns change form:

• kubbur → kubbana
• litabók → litabókina

This is one of the biggest differences from English: the job a noun does in the sentence often changes its ending.

This is a very common Icelandic pattern.

With á:

• á + accusative usually shows movement to a place = onto / to
• á + dative usually shows location in a place = on

Here, the things are being put onto the table, so Icelandic uses the movement/destination pattern:

• á borðið = onto the table

If the objects were already there, you would use the location form:

• Kubbarnir eru á borðinu = The blocks are on the table

So the difference is not just vocabulary, but also case.

In this sentence, it really has the sense of onto, because there is movement toward the table.

English often makes a clearer distinction between:

• on = location
• onto = movement

Icelandic often uses the same preposition, á, and lets the case show the difference.

So:

• á borðið = onto the table
• á borðinu = on the table

The base form is borð, meaning table.

Borðið is the definite singular form, meaning the table.
Because borð is a neuter noun, the definite form here ends in -ið.

So:

• borð = table
• borðið = the table

In this sentence, borðið is the destination of the movement after á.

The dictionary form is morgunmatur (breakfast), but after a preposition like eftir, Icelandic normally uses an oblique case, not the nominative dictionary form.

So the noun appears as:

• morgunmatur = breakfast (dictionary form)
• morgunmat = the form used here after eftir

A useful thing to remember is that many masculine nouns ending in -ur lose that ending outside the nominative.

Because Icelandic, like English, often uses meal words without the definite article when speaking generally.

So:

• eftir morgunmat = after breakfast

This is similar to English, where we usually say after breakfast, not after the breakfast.

If you said eftir morgunmatinn, that would sound more specific, like after the breakfast or after that particular breakfast.

The sentence as written has a very natural, neutral word order:

Við setjum kubbana og litabókina á borðið eftir morgunmat.

But Icelandic word order is fairly flexible, especially with time expressions. For example, you could also say:

Eftir morgunmat setjum við kubbana og litabókina á borðið.

That still means the same thing. The main thing Icelandic cares about in a main clause is that the finite verb tends to stay in second position.

So when Eftir morgunmat comes first, setjum still comes second.

Yes. Icelandic uses compound words very often.

• litabók is made from parts meaning something like color + book
• morgunmatur is literally morning + food

This is very common in Icelandic and often helps learners guess meanings once they know the parts.

Not always. Setja is a broad, common verb meaning put / place / set, so it works well here.

Depending on the exact nuance, Icelandic might sometimes use another placement verb, such as one that suggests laying something down. But setja is a perfectly normal general verb for a learner sentence like this.

So the safest takeaway is:

• setja = a general put/place verb
• it is very common and useful in everyday Icelandic