Contact leads to borrowing: English took "beef," "pork," "justice" from French after 1066.
Bantu languages share features possibly from Khoisan contact.
Pronunciation shifts when speakers adapt foreign sounds; can create new phonemes.
Korean Hangul (15th c.) inspired by Mongolian script from 13th-century invasions.
Intense multi-ethnic contact without shared language creates simplified pidgins; creoles emerge when pidgins become native languages.
Ethnic groups drive revitalization via education, media, literature to preserve endangered languages.
Ethnic interactions continuously reshape languages through borrowing, structural change, new scripts, and new languages.