Breakdown of Kötturinn er í kassa.
vera
to be
kötturinn
the cat
í
in / into / to (before the hour, in telling time) / per (in frequency expressions)
kassinn
the box
Questions & Answers about Kötturinn er í kassa.
Why does the word for box change to kassa instead of its dictionary form kassi?
The preposition í (in) describes a fixed location here, which forces the noun that follows it into the dative case. For the masculine noun kassi, the dative form becomes kassa.
Where is the word for 'a' in í kassa?
Icelandic does not use words for 'a' or 'an' (indefinite articles). You just use the bare noun on its own, so kassa naturally translates to 'a box'.
How do we know kötturinn means 'the cat' and not just 'a cat'?
Unlike English, Icelandic attaches 'the' to the end of the word. Köttur means 'a cat', and adding the definite suffix -inn makes it kötturinn (the cat).
What does it mean that í is a 'static' preposition in this sentence?
It means there is no movement into a new place. The cat is simply existing inside the box. When í shows a static location like this, it takes the dative case. If the cat were jumping into the box, it would trigger a different case!