Abstract: The paper focuses on the use of stylistically marked words used in contemporary English. The aim of our study is to find out the occurrence of both registers: formal and informal. A particular attention is paid to the informal English lexicon as there is a certain shift from neutral communication to more informal communication in contemporary English. Different approaches to the classification of the informal English lexicon will be discussed and illustrated with the samples excerpted from contemporary literary prose. The excerpted samples will be analyzed and classified on the basis of their salient characteristics. Each category will be commented on and examples will be given to demonstrate particular meanings used in different contexts.