Breakdown of Hún vinnur í þessari byggingu en ekki í lestarstöðinni.
hún
she
en
but
ekki
not
í
in / into / to (before the hour, in telling time) / per (in frequency expressions)
Questions & Answers about Hún vinnur í þessari byggingu en ekki í lestarstöðinni.
Why is it þessari byggingu and not þessi bygging?
The preposition í takes the dative case when it means "in" or "inside" a stationary location. The word bygging (building) is a feminine noun, so its dative form is byggingu. The demonstrative pronoun "this" must match it, becoming the feminine dative þessari.
Why does byggingu not have a definite article at the end, while lestarstöðinni does?
In Icelandic, when you use a demonstrative pronoun like þessari (this), you usually drop the definite article on the noun. So it is just í þessari byggingu (in this building). But for the train station, we want to say "in the train station", so we attach the definite article to make í lestarstöðinni.
How is the word lestarstöðinni formed?
It comes from lest (train) and stöð (station). When combining them, lest goes into the genitive (possessive) case, becoming lestar-, giving us lestarstöð. Then we add the feminine dative definite article -inni to match the preposition í, resulting in lestarstöðinni.
Doesn't the preposition í sometimes take the accusative case? Why is it dative here?
Yes, í takes the accusative case when it describes movement into a place. But when it describes being stationary inside a place, like working in a building or a train station, it forces the noun into the dative case.