North American English (NAmE) encompasses the English language as spoken in both the United States and Canada. Because of their related histories and cultures, plus the similarities between the pronunciations (accents), vocabulary, and grammar of U.S. English and Canadian English, linguists often group the two together. Canadians are generally tolerant of both British and American spellings, although certain words always take British spellings (e.g., cheque rather than check) and others American spellings (e.g., tire rather than tyre).
Dialects of English spoken by United Empire Loyalists who fled the American Revolution (1775–1783) have had a large influence on Canadian English from its early roots. Some terms in North American English are used almost exclusively in Canada and the United States (for example, the terms diaper and gasoline are widely used instead of nappy and petrol). Although many English speakers from outside North America regard those terms as distinct Americanisms, they are just as common in Canada, mainly due to the effects of heavy cross-border trade and cultural penetration by the American mass media. The list of divergent words becomes longer if considering regional Canadian dialects, especially as spoken in the Atlantic provinces and parts of Vancouver Island where significant pockets of British culture still remain.