The Preposition aus

The preposition aus takes the dative. We use it to describe a person’s origin.
 

It describes the material composition of things.
 

Finally, it is used to describe the ideas "emerging from" or "out of."
 

The Preposition von

The preposition von takes the dative and describes relationships of ownership or authorship.
 

Von also describes the point of departure of something or somebody.

The Preposition bei

Use the preposition bei with dative to express these meanings which share the common notion of "close association with."

at X’s home, as X’s guest
 

in X’s office
 

to/in X company, organization
 

The Contractions vom and beim

The contraction for von + dem is vom. The contraction for bei + dem is beim. The feminine forms and plural forms are not contracted with either preposition.
 

Examples of aus, von, and bei

• Frau Ritzerfeld. Hier ist Michael Smith aus Atlanta. Kann ich mit Frau Hübner sprechen?
• Heiner Höyng. Es freut mich, Herr Smith. Willkommen bei der Firma Schuchardt.
• Waren Sie schon beim Arzt?