Twitter Users #CodeSwitch Hashtags! #MoltoImportante #wow

When code switching, individuals incorporate elements of multiple languages into the same utterance. While code switching has been studied extensively in formal and spoken contexts, its behavior and prevalence remains unexamined in many newer forms of electronic communication. The present study examines code switching in Twitter, focusing on instances where an author writes a post in one language and then includes a hashtag in a second language. In the first experiment, we perform a large scale analysis on the languages used in millions of posts to show that authors readily incorporate hashtags from other languages, and in a manual analysis of a subset the hashtags, reveal prolific code switching, with code switching occurring for some hashtags in over twenty languages. In the second experiment, French and English posts from three bilingual cities are analyzed for their code switching frequency and its content.