cognition psycholinguistics language and thought grammar connotation usa linguistic relativity colonialism europe slang syntax identity politics Sapir-Whorf hypothesis phonetics historical linguistics language learning communication accommodation theory stereotypes alphabet ambiguity accent ancient greece sociolinguistics brain communication ancient history spain ai language spanish language 20th century language evolution comparative method vocabulary china etymology social status language and culture contact language computational linguistics acoustic phonetics language change language history anatomy britain ancient languages french conquistadors phonology spanish is linguistic diversity loanwords french language japanese language 19th century ancient rome latin africa colonialism esperanto italian language english language africa shakespeare semantics writing systems latin language accents german american english language lernen pragmatics writing system cross-cultural communication history