 Native English speakers would have some command of Chinook Jargon when immigrating from other places in the Northwest, and as a consequence would tend towards using it rather than English with monolingual Tlingit speakers.Oral history confirms that many Tlingit speakers in the late 19th and early 20th century were also fluent in Chinook Jargon, some even with native proficiency.Because the two languages coexisted, it is often difficult to tell whether a particular borrowing is taken directly from English into Tlingit, or instead whether it was imported through the intermediary of Chinook Jargon.