A preposition links two parts of a sentence: a verb and a place, a noun and a time, an action and a reason. In English, the preposition itself rarely changes anything else around it. In German, every preposition decides the case of the noun phrase that follows it. Learn the preposition, and you already know whether der becomes den, dem, or des.
Some prepositions only take the Akkusativ
A small fixed group of prepositions always sends the following noun phrase into the Akkusativ, and you never have to read the context to be sure.
| Preposition | Meaning | Example |
|---|---|---|
| durch | through | Ich gehe durchden Park |
| für | for | Das ist fürdich |
| ohne | without | Ich gehe ohneden Schlüssel |
| um | around / at (time) | Wir sitzen umden Tisch |
Some prepositions only take the Dativ
A second fixed group works just as automatically, always sending the following noun phrase into the Dativ.
| Preposition | Meaning | Example |
|---|---|---|
| mit | with | Ich gehe mitdem Freund |
| bei | at / with / near | Ich bin beider Arbeit |
| nach | after | Ich fahre nacheiner Woche |
| von | from / of / by | Das ist voneinem Freund |
Two of the fixed Dativ prepositions deserve their own look → zu and aus both describe movement, to a place or out of a place, and a learner's instinct is often to expect the Akkusativ for movement. These two stay Dativ regardless.
Two-way prepositions → the verb decides
A third group can take either the Akkusativ or the Dativ, and the choice depends on the verb in the sentence, not on the preposition itself. Verbs of movement to a destination take the Akkusativ. Verbs describing a fixed location take the Dativ.
| Preposition | Location (Dativ) | Direction (Akkusativ) |
|---|---|---|
| in | Ich bin inder Küche | Ich gehe indie Küche |
| an | Es hängt ander Wand | Ich hängees andie Wand |
| auf | Es liegt aufdem Tisch | Ich legees aufden Tisch |
A few prepositions take the Genitiv
The smallest group sends the following noun phrase into the Genitiv. These mostly appear in writing and formal speech, where the Genitiv itself survives most strongly.
| Preposition | Meaning | Example |
|---|---|---|
| während | during | Währenddes Kurses war ich krank |
| trotz | despite | Trotzdes Regens sind wir gegangen |
| wegen | because of | Wegender Arbeit bin ich müde |
Prepositions can merge with articles
Several prepositions regularly contract with the definite article into a single word. These contractions are standard, not informal shortcuts, and the case underneath them does not change.
| Preposition + article | Contraction |
|---|---|
| in + dem | im |
| an + dem | am |
| zu + dem | zum |
| bei + dem | beim |
| in + das | ins |
| an + das | ans |
Every German preposition decides the case of what follows it. durch für ohne um and the rest of their group are always Akkusativ. mit bei nach von and the rest of their group are always Dativ. in an auf and the other two-way prepositions switch between Akkusativ and Dativ depending on whether the verb describes direction or location. And während trotz wegen take the Genitiv. Learn the preposition, and the case comes with it for free.