How do German prepositions affect case?

German prepositions control the case of the noun or pronoun that follows them. Some always take accusative , some always take dative , and some can take either depending on meaning.

What are two-way prepositions, and how do I know whether to use accusative or dative?

Two-way prepositions like in, an, and auf can take either case. Use accusative for movement or direction, and dative for location or position: Ich gehe in den Park vs. Ich bin im Park .

Why do Germans use words like "damit" and "wofür" instead of "mit es" or "für was"?

German often replaces preposition + pronoun with a single pronominal adverb like damit, darauf, wofür . This sounds more natural and is the standard way to say things like "with it" or "for what?".

Prepositions (Präpositionen) — The Case Controllers 🕹️

Prepositions link nouns or pronouns to other words, establishing relationships of time, place, or logic (in, an, für, mit). In German, each preposition acts as a strict boss, demanding that the following noun takes either the Accusative, Dative, or Genitive case.

Infographic describing German Prepositions (Präpositionen) and how they dictate grammatical case.

Prepositions are small words like in, at, on, for, with.
They connect nouns to the rest of the sentence.
In German, they are powerful dictators: They decide the Case of the next word.

1. Accusative Prepositions (The FUDGE) 🍫

These ALWAYS require the Accusative.

Für, Um, Durch, Gegen, Entlang.
Für mich. (Not mir).

2. Dative Prepositions (The Blue Danube) 🌊

These ALWAYS require the Dative.

Aus, Bei, Mit, Nach, Seit, Von, Zu.
Mit dir. (Not dich).

3. Two-Way Prepositions (The Switchers) 🔛

These can be Accusative OR Dative, depending on "Movement vs. Position".

In, An, Auf, Neben...
Ich gehe in den Park. (Movement -> Acc).
Ich bin im Park. (Position -> Dat).

4. Genitive Prepositions (The Fancy Ones) 🎩

Wegen, Trotz, Während...
Wegen des Wetter*s.*

👉 Deep Dive: Go to the Prepositions Category to learn them all.

5. The "Pronominal Adverbs" (Da- & Wo-) 🏗️

Germans hate saying "Preposition + It".
Instead of "with it" (mit es), we say "damit" (there-with).
Instead of "for what?" (für was?), we say "wofür?" (where-for).

Ich warte darauf. (I wait for it).
Ich habe Angst davor. (I have fear of it).

👉 Deep Dive: Learn this magic trick at Pronominal Adverbs.