Barnið sá sýninguna í gær.

A simple breakdown is:

• Barnið = the child
• sá = saw
• sýninguna = the show / the exhibition
• í gær = yesterday

So the structure is basically:

• subject: Barnið
• verb: sá
• object: sýninguna
• time expression: í gær

This is a very normal Icelandic sentence pattern.

Because barnið is the definite form of barn, which means child.

• barn = child
• barnið = the child

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

Also, barn is a neuter noun, and -ið is the definite ending here.

Sá is the past tense of the verb sjá, which means to see.

So:

• sjá = to see
• sá = saw

In this sentence, sá is the 3rd person singular past form, used with barnið = the child.

This verb is irregular, so you cannot predict sá just by adding a regular past-tense ending.

Yes. Sá can also be a demonstrative word meaning something like that or that one in other contexts.

But here it is clearly the verb saw, because of the sentence structure:

• Barnið = subject
• sá = verb
• sýninguna = object

So in this sentence, sá is not a demonstrative; it is the past tense of sjá.

Because it is the direct object of the verb sá, and the verb sjá normally takes the accusative case.

The base noun is:

• sýning = show / exhibition

But here we need:

• accusative singular definite = sýninguna

So the ending tells you two things at once:

• it is definite = the show
• it is in the accusative because it is the thing being seen

That is why you get sýninguna, not just sýning.

Because Icelandic usually puts the definite article onto the end of the noun.

So instead of a separate word like English the, Icelandic often uses a suffix:

• barn → barnið = the child
• sýning → sýninguna = the show / the exhibition

This is one of the first big differences English speakers notice in Icelandic.

Í gær means yesterday.

You should learn it as a fixed expression. Even though í is often a preposition meaning in, in í gær the whole phrase simply means yesterday.

So it is best not to translate it too literally word for word. Just remember:

• í gær = yesterday

Yes, but Icelandic has an important rule: the finite verb usually stays in second position in main clauses.

The sentence you have is the neutral order:

• Barnið sá sýninguna í gær.

You can also move the time expression to the front:

• Í gær sá barnið sýninguna.

That is still correct, and it may put a little more focus on yesterday.

But because of the verb-second rule, you do not say:

• Í gær barnið sá sýninguna. ✗

So Icelandic word order is flexible, but not completely free.

• barn is neuter
• sýning is feminine

Gender matters in Icelandic because it affects things like:

• definite endings
• adjective endings
• pronouns
• some other agreement patterns

In this sentence, you can already see gender affecting the noun forms:

• barnið uses a neuter definite ending
• sýninguna uses a feminine accusative definite ending

So even when English does not care about noun gender, Icelandic often does.

It can mean several related things depending on context, including:

• show
• exhibition
• screening
• performance in some situations

So sýninguna could be translated in different ways depending on what was already being talked about.

If the meaning has already been given to you, use that meaning for the sentence, but it is good to know that the Icelandic word can be a bit broader than a single English word.

Because the endings and the sentence structure show their roles.

• barnið is the one doing the seeing, so it is the subject
• sýninguna is the thing being seen, so it is the object

A big clue is the case marking:

• sýninguna is clearly accusative, which is exactly what you expect for the object of sjá
• barnið is the nominative-form subject here

So Icelandic often tells you grammatical roles not only by word order, but also by noun endings.

A few useful pronunciation notes:

• á in sá sounds roughly like ow in now
• ý in sýninguna sounds like ee in see
• ð in barnið is the letter called eth, usually like th in this
• æ in gær sounds roughly like eye

Also, Icelandic usually stresses the first syllable of a word, so:

• BAR-nið
• SÁ
• SÝn-ing-una
• Í gær

The exact pronunciation takes practice, but those approximations are a good start.