Learn Icelandic: Nytjamarkaðurinn er fullur af skrító hlutum. - The thrift store is full of weird things.

The suffix -ó is added to the root of skrítinn (weird) to create a casual, colloquial slang word. A key feature of these -ó adjectives is that they are totally indeclinable. That is why skrító stays exactly the same, even though it modifies the dative plural noun hlutum.

What is the literal breakdown of the word Nytjamarkaðurinn?

It is a compound of nytja, which is the genitive plural of nytj (use, utility, or benefit), and markaðurinn (the market). So, it literally translates to 'the market of utilities' or 'the market of used things', which is the standard Icelandic term for a thrift store.

Why is hlutum in the dative case?

It is governed by the preposition af. When you say something is 'full of' something else in Icelandic, you use fullur af, and the preposition af always forces the noun that follows it into the dative case.

Why does fullur end in -ur here instead of taking a neutral form?