Feluleikur er uppáhalds leikurinn hennar, og barnið vill alltaf fela bangsann líka.

Because er is a linking verb (to be), not an action verb taking a direct object.

In Icelandic, when two nouns are linked by vera and one identifies the other, both are normally in the nominative:

• Feluleikur = nominative
• leikurinn = nominative

So the structure is basically:

• Feluleikur = hide-and-seek
• er = is
• uppáhalds leikurinn hennar = her favorite game

It is not “Hide-and-seek does her favorite game” or anything like that, so there is no accusative object here.

Yes. Feluleikur is a compound noun meaning hide-and-seek.

It is built from:

• fela = to hide
• leikur = game

So literally it is something like hiding-game.

Compounds are extremely common in Icelandic, so seeing a whole idea packed into one word is very normal.

Uppáhalds means favorite.

Grammatically, it behaves like a fixed modifier before a noun:

• uppáhalds leikurinn = the favorite game
• uppáhalds bók = favorite book
• uppáhalds matur = favorite food

A useful thing to know is that uppáhalds usually does not change form the way ordinary adjectives often do. So learners often just treat it as a set word meaning favorite.

Because Icelandic usually places possessive words like hans, hennar, and þeirra after the noun.

So:

• leikurinn hennar = her game
• barnið hennar = her child
• húsið þeirra = their house

This is one of the most common patterns in Icelandic. English usually puts the possessive first (her game), but Icelandic very often puts it after the noun.

This is a very common Icelandic pattern.

When Icelandic uses a noun with a following possessive, the noun is often definite:

• leikurinn hennar = literally the game of hers
• bíllinn minn = my car
• bókin hans = his book

So even though English does not say the her favorite game, Icelandic naturally uses the definite form here.

That is why you get:

• uppáhalds leikurinn hennar

not just:

• uppáhalds leikur hennar

The noun barn (child) is grammatically neuter in Icelandic.

Its definite singular form is:

• barn = a child
• barnið = the child

So the -ið is the suffixed definite article, attached to the noun itself.

Also, grammatical gender does not necessarily match real-world sex. A child can be a boy or a girl, but the noun barn is still neuter.

Because vilja (to want) is followed by an infinitive.

So:

• barnið vill fela bangsann = the child wants to hide the teddy bear

Here:

• vill = present tense, wants
• fela = infinitive, to hide

This is similar to English wants to hide, except Icelandic does not use a separate word like to in this construction.

Because bangsann is the declined form used here for the teddy bear as the direct object of fela.

The basic dictionary form is:

• bangsi = teddy bear

But in the sentence, it is the thing being hidden, so it appears in the appropriate object form, here with the definite ending:

• bangsann = the teddy bear

So the key idea is:

• fela takes a direct object
• that object changes form
• Icelandic nouns often change quite a bit when declined

In this sentence:

• alltaf = always
• líka = also / too

Their placement is normal Icelandic word order:

• barnið vill alltaf fela bangsann líka

A helpful way to read it is:

• barnið vill alltaf = the child always wants
• fela bangsann = to hide the teddy bear
• líka = too / also

So alltaf comes after the finite verb vill, which is very common in Icelandic main clauses.

And líka often appears late in the sentence, especially when it means too/as well.

Yes. Here líka means also / too.

That can be confusing because líka can also be a verb meaning to like in other contexts.

But here it is clearly the adverb also because of the structure:

• barnið vill alltaf fela bangsann líka

It is adding the idea too / as well, not expressing liking.

So here the sentence is not saying the child likes the teddy bear. It is saying the child wants to hide the teddy bear too.