Breakdown of Lykillinn er í töskunni.
vera
to be
í
in / into / to (before the hour, in telling time) / per (in frequency expressions)
lykillinn
the key
taskan
the bag
Questions & Answers about Lykillinn er í töskunni.
Why is the bag in the dative case here?
The preposition í (in) takes the dative case when it describes a stationary location, meaning where something is resting or located. Since the key is just sitting inside the bag, töskunni must be in the dative case.
What is the base dictionary word for töskunni, and how is the ending formed?
The base word is taska (a bag), which is a feminine noun. In the dative case, it becomes tösku. To say the bag in the dative case, we add the definite feminine dative ending -nni to get töskunni.
Why does the first vowel in taska change to ö in töskunni?
This is a common vowel shift in Icelandic. When a feminine noun ending in -a like taska changes its ending to a -u in the dative case (tösku), the a earlier in the word changes to an ö. This shifted vowel stays even when we add the definite ending -nni to the end.
Why doesn't lykillinn change its case like the bag does?
Lykillinn (the key) is the subject of the sentence, meaning it is the thing doing the action (in this case, just being). The subject of a sentence is always in the nominative or basic case. Only the noun following the preposition í gets affected and forced into the dative case.