A special category of prepositions takes either the accusative or the dative case.
auf on, onto
in in, into
neben next to
vor in front of, before
Use the dative case when the prepositional phrase shows location. Use the accusative case when the prepositional phrase shows movement from one place to another. This involves a verb of motion, for example: gehen, fahren, fliegen, and so on.
Die Kinder stehen am Fenster. The children are standing by the window.
Er verbirgt sich hinter einem Baum. He’s hiding behind a tree.
Die Katze schläft unter dem Tisch. The cat is sleeping under the table.
Gudrun sitzt zwischen ihren Eltern. Gudrun is sitting between her parents.
These phrases tell where someone or something is, and the dative case is, therefore, used with these prepositions.
Let’s look at some examples where these prepositions take the accusative case. In each example, a verb shows movement from one place to another: stellt, läuft, fliegen, and legte. When such verbs are followed by an accusative-dative preposition, the accusative case is used.
Sie stellt eine Lampe hinter die Gardine. She places a lamp behind the curtains.
Der Junge läuft in die Küche. The boy runs into the kitchen.
Die Vögel fliegen über den Fluss hinüber. The birds fly across the river.
Er legte Zeitungspapier unter den Tisch. He laid newspaper under the table.
In each of the following examples, the verb of the sentence is not a verb of motion: warten, denke, verliebte, and sprechen. Normally this would mean that the accusative-dative prepositions should take the dative case. However, the dative case would indicate location, which is not what the prepositional phrases in these examples indicate. Therefore, the accusative case is required instead.
Auf wen warten Sie? For whom are you waiting?
Ich denke oft an meine Familie. I often think about my family.
Martin verliebte sich in sie. Martin fell in love with her.
Alle sprechen über den Unfall. Everyone’s talking about the accident.
A list of commonly used verbs that are accompanied by accusative-dative prepositions follows. The case required by the preposition is indicated by the letter A for accusative or D for dative. Take note that some of the verbs that actually do not indicate location still require the dative case.
achten auf A pay attention to
sich beklagen über A complain about
denken an A think about
sich erinnern an A remember, remind of
erkennen an D recognize by
sich freuen auf A look forward to
sich freuen über A be glad about
glauben an A believe in
hoffen auf A put faith in, hope for
sich irren in A be wrong about
leiden an D suffer from
reden über A talk about
schreiben an A write to
schreiben über A write about
schützen vor D protect from
sprechen über A speak about
sterben an D die from
teilnehmen an D take part in
sich verlassen auf A rely on
sich verlieben in A fall in love with
verzichten auf A do without
warnen vor D warn against
warten auf A wait for
In questions that inquire into motion or location, use wohin to ask to what place someone or something is going and use wo to ask where someone or something is located. For example:
accusative in die Schule Wohin? into the school Where to? (To what place?)
dative in der Schule Wo? in the school Where?
Notice that this use of wohin and wo corresponds to the use of the accusative-dative prepositions. This difference of meaning in location and motion caused by the use of the dative or the accusative case occurs with both nouns and pronouns. Also remember that if a pronoun refers to an inanimate object, a prepositional adverb is used instead of a prepositional phrase. For example:
daneben next to it
darin in it
worauf on what
wovor in front of what