Complex sentence: In 1959, Quirk founded the Survey of English Usage, working with Valerie Adams, Derek Davy and David Crystal, sampled written and spoken British English produced between 1955 and 1985.
Split into simpler sentences: In 1959, Quirk founded the Survey of English Usage. This ambitious project, early co-workers on which included Valerie Adams, Derek Davy and David Crystal, sampled written and spoken British English produced between 1955 and 1985.