Linguistically Shelta is today seen as a mixed language that stems from a community of travelling people in Ireland that was originally predominantly Irish-speaking. The community later went through a period of widespread bilingualism that resulted in a language based heavily on Hiberno-English with heavy influences from Irish. As different varieties of Shelta display different degrees of anglicisation, it is hard to determine the extent of the Irish substratum. The "Oxford Companion to the English Language" puts it at 2,000–3,000 words.