Always accusative, always dative
These prepositions never change their case. German learners often memorise them as sing-song lists: “durch, für, gegen, ohne, um” and “aus, bei, mit, nach, seit, von, zu”.
Two-way prepositions: the wohin / wo test
Ask which question the phrase answers. Wohin? (where to?) means movement towards a new place: accusative. Wo? (where?) means a position, even if something moves within it: dative. Choose a preposition to see both cases.
Verb pairs: putting and being
German has matching verb pairs for placing something and for where it then is. The “putting” verb is regular and takes the accusative; the “being” verb is strong and takes the dative. English uses “put” and “is” for all of them; German specifies the position.
| Position | Put it there · accusative | It is there · dative |
|---|---|---|
| lying flat | ||
| standing up | ||
| hanging |
Contractions: im, am, zum, zur, ins
Common prepositions merge with dem, der or das into one word. The merged forms are normal in both speech and writing; the separate forms are only used for emphasis (“in dem Haus”, in that house).
Prepositions of time
Time expressions use a different preposition for each size of time unit. All of these take the dative except um and für.
Genitive prepositions
A small group takes the genitive. You will meet them in news, forms and formal writing. In everyday speech, many people use the dative after wegen and trotz instead (wegen dem Wetter), which is widely accepted in conversation.