preposition
in
A1
in is the German preposition meaning 'in'. It's a two-way (accusative or dative) preposition: use accusative for movement toward a destination (Ich gehe in die Schule) and dative for location (Ich bin in der Schule). No fixed object preposition; case changes meaning of motion vs. location.
Examples
Die Konferenz fand in der Stadt statt, nachdem die Organisatoren den Termin verschoben hatten, weil viele Teilnehmer absagten.
The conference took place in the city after the organizers had postponed the date because many participants canceled.
Ich bin in der Schule.
I'm at school.
Details
Mnemonics
Picture going into a room — you're moving 'in' the room
same as English 'in'
Notes
Two-way preposition: takes accusative for movement toward (motion), dative for location (no motion).