On this page you'll learn everything about verbs with preposition complements. Complements are grammatically necessary parts of a sentence. If you aren't sure what that means, take a look at this page on complements in the German language.
Some verbs require prepositions to make sense and be grammatically correct.
Without the prepositions the verb doesn‘t work or has a different meaning.
The preposition always determines the case (dative/accusative/genitive).
Some verbs even require two complements with two different prepositions:
("Sprechen" and "bedanken" have 2 complements. When one piece of information is unknown or obvious, we can leave it out. The prepositions determine the case.)
When forming a question with a verb that uses a prepositional complement, we have to include the preposition in the question word.
We simply put the preposition in front of the question word "wen" (for accusative) or "wem" (for dative). This is similar to "With whom..?" , "By whom...?," etc. in English.
The question word is constructed by "wo" + preposition. For prepositions that start with a vowel ("a," "e," "i," "o," "u"), we have to also include an "r."
These questions have nothing to do with the question word "Wo?" (Where?)
The following version is also possible, but is very informal (and some say it sounds dumb):
Some verbs have prepositional complements: That doesn’t mean that you ALWAYS have to include that preposition. It just means that without the preposition or with a different preposition, there is a different meaning.
The preposition always determines the case.
If you want to ask a question where a prepositional phrase is the answer, you have to include the preposition in the question.
All the info you need for the various complements in German: