A number of German words have made their way into the English language. Some of them we accept as a matter of course as they have been around for a long time. Others, have come into English rather recently. While most words maintain the same or similar meaning some change their meaning slightly when transplanted from one language to another. For example, the word angst. Below you will find a list of common German words and phrases used in English.
Achtung! (careful/watch out)
die Angst (fear in German)
das Aspirin
der Dachshund (wiener dog)
der Doppelganger (a body double/look-alike)
der Ersatz (substitute)
das Fest (party in German ex. filmfest)
Gesundheit! (health: used when someone sneezes)
der Hamburger
kaput (broken/not working)
der Kindergarten
der Poltergeist
der Rucksack
die Schadenfreude (taking pleasure in someone else’s misfortune!)
verboten (not allowed/prohibited)
die Wanderlust
das Wunderkind
German Präfixes (prefixes) can also be used in English, particularly: über
He is überpatient with his wife. (This implies he is extremely or too patient with his wife)
For a longer list visit: http://german.about.com/library/blvoc_gerloan2.htm