Barnið fær að velja hvort það vill jógúrt eða kex í nesti á morgun.

Barn means child in the indefinite sense, while barnið means the child.

The ending -ið is the suffixed definite article for a neuter singular noun. So:

• barn = a child
• barnið = the child

This is very common in Icelandic: instead of a separate word like the, Icelandic usually adds the article to the end of the noun.

Here fær is from the verb fá, which often means get or receive. But when fá is followed by að + infinitive, it usually means get to do something, be allowed to do something, or have the opportunity to do something.

So:

• fær að velja = gets to choose / is allowed to choose

This is a very useful pattern:

• Ég fæ að fara. = I get to go.
• Hún fær að tala. = She gets to speak.

Hvort means whether and introduces an indirect yes/no choice.

In this sentence, the child is choosing between two possibilities, so hvort ... eða ... is the natural structure:

• hvort það vill jógúrt eða kex = whether it wants yogurt or crackers/cookies

A good way to think of it is:

• hvort = whether
• eða = or

So the structure is literally something like whether it wants yogurt or kex.

Because barn is a neuter noun in Icelandic, the pronoun that refers back to it is það.

So:

• barnið = the child
• það = it

This may feel strange to an English speaker, because English often prefers he or she for a child if the gender is known. But in Icelandic, using það with barn is completely normal because the grammar follows the noun’s gender.

Vill is the 3rd person singular present tense of vilja, meaning to want.

So:

• ég vil = I want
• þú vilt = you want
• það vill = it wants

In the sentence, the subject is það, so vill is the correct form.

They are the direct objects of velja and vill, so they are in the accusative.

However, in this sentence, you do not see a special accusative ending, because these nouns either do not change form here or look the same as in the nominative.

So even though the case is accusative, the forms stay:

• jógúrt
• kex

This is very common in Icelandic: not every noun shows a visible change in every case.

Because the sentence is talking about the foods in an indefinite, general way: yogurt or kex, not the yogurt or the kex.

Icelandic often leaves food nouns without the definite article in this kind of context, especially when talking about what someone wants, eats, buys, or chooses.

So this sounds natural:

• vill jógúrt = wants yogurt
• vill kex = wants kex

If you added the definite article, it would sound more like a specific known yogurt or a specific known package/type already identified in the conversation.

In Icelandic, kex is often used as a mass noun or collective food word, much like English can say some crackers, some cookies, or just cracker/cookie type food in a general sense.

So in this sentence, kex does not necessarily mean exactly one biscuit/cookie. It means the food item kex as an option.

That is why English translations can vary depending on context:

• yogurt or crackers
• yogurt or cookies
• yogurt or a biscuit

The Icelandic word itself is often left unchanged.

Nesti means something like packed lunch, provisions, or food taken along.

So í nesti means in the packed lunch or more naturally in English for the packed lunch / as part of the lunch brought along.

In this sentence, it means the child is choosing what will be included in tomorrow’s lunch/snack pack.

The preposition í can take either:

• accusative for motion into something
• dative for location or state in something

Here there is no motion into something. The meaning is more like in/for the lunch pack, so dative is used.

With nesti, the form happens to look the same, so you do not see a change. But grammatically this is understood as dative here.

Á morgun means tomorrow.

This is a fixed Icelandic expression:

• á morgun = tomorrow
• í morgun = this morning

That difference is important, because English speakers often confuse them at first. Even though both use a preposition plus morgun, they are not interchangeable.

So in your sentence:

• á morgun = tomorrow

Yes, a sentence with má velja would also be possible, but the nuance is a little different.

• má velja = may choose / is allowed to choose
• fær að velja = gets to choose / is allowed the opportunity to choose

Fær að velja often sounds a bit more like being given the chance or privilege to choose, while má velja focuses more directly on permission.

So barnið fær að velja feels very natural if you mean the child is being given the option.