North American English
North American English (NAmE, NAE) is the most generalized variety of the English language as spoken in the United States and Canada. Because of their related histories and cultures, plus the similarities between the pronunciations (accents), vocabulary, and grammar of American English and Canadian English, the two spoken varieties are often grouped together under a single category. Canadians are generally tolerant of both British and American spellings, with British spellings of certain words (e.g., "colour") being favored in more formal settings and in Canadian print media; for some other words the American spelling prevails over the British  (e.g., "tire" rather than "tyre"). The 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. There are a considerable number of different accents within the regions of both the United States and Canada. English in North America originally derived from the accents prevalent in different English, Scottish and Irish regions of the British Isles. These were developed, built upon, and blended together as new waves of immigration, and migration across the North American continent, developed new accents and dialects in new areas, and as these ways  of speaking merged and assimilated with the English-speaking population. Dialects. American English. Ethnic American English Regional American English Table of accents. Below, thirteen major North American English accents are defined by particular characteristics: Phonology. A majority of North American English (for example, in contrast to British English) includes phonological features that concern consonants, such as rhoticity (full pronunciation of all sounds), conditioned T-glottalization (with "satin" pronounced , not ), T- and D-flapping (with "metal" and "medal" pronounced the same, as ), L-velarization (with "filling" pronounced , not ), as well as features that concern vowel sounds, such as various vowel mergers  before (so that, "Mary", "marry", and "merry" are all commonly pronounced the same), raising of pre-voiceless (with "price" and "bright" using a higher vowel sound than "prize" and "bride"), the weak vowel merger (with "affected" and "effected" often pronounced the same), at least one of the vowel mergers (the – merger is completed among virtually all Americans and the – merger among nearly half, while both are completed among virtually all Canadians), and yod-dropping (with "tuesday" pronounced , not ). The last item is more advanced in American English than Canadian English.