Konglish is the language often used among Korean-Americans. As is common for many subcultures in the United States, Korean Americans mix Korean with English as they speak with each other.
A Konglish dialog often consists of English verbs with Korean nouns, or English nouns with Korean verbs. The more popular form is to use the English grammar with English verbs, and using a mix of English and Korean nouns. Pronouncing words of one language with the accent of the other is often accepted, but using incorrect spelling or grammar (at least in English form) is usually not accepted.
Although Konglish is spoken mostly by 1st, 1.5-th, and 2nd generation Korean Americans, it often influences anyone around Korean Americans, including friends, family, and relatives. It is known to be quite contagious.
See also: Janglish, Engrish, Chinglish, Spanglish