Riekspiel

Riekspiel is the original language of the Empire of Man and the Old World that Was during the World that Was].
Riekspiel is official language in New Kislev, the unofficial language in United States of Hammerica, and is also spoken in East Landlockia and West Landlockia, though with very distinct accents.
Many, but far from all people in the West, make it a point to Learn Riekspiel. By an astonishing coincidence, Riekspiel sounds very similar to American English with old western slang thrown in.