The Preposition "in" and its contractions

The preposition in takes the dative to describe enclosure. The contraction for in + dem is im.
 

Before feminine singular nouns, its form is in plus the definite article der:
 

The Prepositions "für" and "um"

The prepositions für and um take the accusative:
 

Characteristic Prepositions with Verbs

In certain verbal expressions, only one specific characteristic preposition may be used to express a certain meaning. An English example is "to look at." Just from the meaning of the preposition "at," it seems logical that you should also be able to say:
 

English usage doesn’t admit this "logic" and requires us to say:

German behaves similarly. Certain verbs have characteristic prepositions needed to complete their meaning in a certain way. As in the English examples above, the meaning of the preposition otherwise is no help in deciding logically whether it is the right one for this verb. "Fragen nach" is one example. It means "to ask about." fragen nach takes a dative object.
 

These verb plus characteristic preposition combinations will be noted in the vocabulary. Here are the ones we have had so far.

sprechen über (+ accusative)–to speak about
 

wechseln in (+ accusative)–to change into
 

umtauschen in (+ accusative)–to change into
 

drücken auf (+ accusative)–to push (on)
 

Examples of in, für, and um

• Dann nehmen Sie die S-Bahn zum Hauptbahnhof. Das Parkhotel ist gleich um die Ecke vom Taxistand.
• Ja. Wo finde ich das CNN-Programm im Fernsehen?
• Wir suchen eine Wohnung für uns und unsere beiden Kinder.