The English language was introduced to the Americas by the arrival of the English, beginning in the late 16th century. The language also spread to numerous other parts of the world as a result of British trade and settlement and the spread of the former British Empire, which, by 1921, included 470–570 million people, about a quarter of the world's population. In England, Wales, Ireland and especially parts of Scotland there are differing varieties of the English language. Likewise, spoken American English varies widely across the country. Written forms of British and American English as found in newspapers and textbooks vary little in their essential features, with only occasional noticeable differences.Even in vocabulary. "A British reader of Time or Newsweek would note distinctly American expressions only a few times on any page, matching the few distinctly British expressions an American reader of The Economist would note." Edward Finegan in Language in the USA: Themes for the Twenty-first Century. Eds Charles Albert Ferguson, Edward Finegan, Shirley Brice Heath, John R. Rickford (Cambridge University Press, 2004). p. 29. See also: David Crystal, The Cambridge Encyclopedia of the English Language (Cambridge University Press, 2003), p. 304.

Over the past 400 years, the forms of the language used in the Americas—especially in the United States—and that used in the United Kingdom have diverged in a few minor ways, leading to the versions now often referred to as American English and British English. Differences between the two include pronunciation, grammar, vocabulary (lexis), spelling, punctuation, idioms, and formatting of dates and numbers. However, the differences in written and most spoken grammar structure tend to be much fewer than in other aspects of the language in terms of mutual intelligibility. A few words have completely different meanings in the two versions or are even unknown or not used in one of the versions. One particular contribution towards integrating these differences came from Noah Webster, who wrote the first American dictionary (published 1828) with the intention of unifying the disparate dialects across the United States and codifying North American vocabulary which was not present in British dictionaries.

This divergence between American English and British English has provided opportunities for humorous comment: e.g. in fiction George Bernard Shaw says that the United States and United Kingdom are "two countries divided by a common language";See, for example, Krueger CL, Stade G, Karbiener K, Encyclopedia of British Writers: 19th and 20th Centuries Book Builders LLC Infobase Publishing , p. 309 and Oscar Wilde says that "We have really everything in common with America nowadays, except, of course, the language" (The Canterville Ghost, 1888). Henry Sweet incorrectly predicted in 1877 that within a century American English, Australian English and British English would be mutually unintelligible (A Handbook of Phonetics). Perhaps increased worldwide communication through telecommunications has tended to reduce regional variation. This can lead to some variations becoming extinct (for instance the wireless being progressively superseded by the radio) or the acceptance of wide variations as "perfectly good English" everywhere.

Although spoken American and British English are generally mutually intelligible, there are occasional differences which may cause embarrassment—for example, in American English a rubber is usually interpreted as a condom rather than an eraser.

Word derivation and compounds British English uses possessive more frequently than American English. Compare doll's house and baby's bottle with dollhouse and baby bottle. Directional suffix -ward(s): British forwards, towards, rightwards, etc.; American forward, toward, rightward. In both varieties distribution varies somewhat: afterwards, towards, and backwards are not unusual in the United States; while in the United Kingdom upward and rightward are the more common options, as is forward, which is standard in phrasal verbs such as look forward to. The forms with -s may be used as adverbs (or preposition towards) but rarely as adjectives: in the UK, as in the United States, one says "an upward motion". The Oxford English Dictionary in 1897 suggested a semantic distinction for adverbs, with -wards having a more definite directional sense than -ward; subsequent authorities such as Fowler have disputed this contention. American English (AmE) freely adds the suffix -s to day, night, evening, weekend, Monday, etc. to form adverbs denoting repeated or customary action: I used to stay out evenings; the library is closed on Saturdays. This usage has its roots in Old English but many of these constructions are now regarded as American (for example, the OED labels nights "now chiefly N. Amer. colloq." in constructions such as to sleep nights, but to work nights is standard in British English). In British English (BrE), the agentive -er suffix is commonly attached to football to refer to one who plays the sport (also cricket; often netball; occasionally basketball and volleyball). AmE usually uses football player. Where the sport's name is usable as a verb, the suffixation is standard in both varieties: for example, golfer, bowler (in ten-pin bowling and in lawn bowls), and shooter. AmE appears sometimes to use the form baller as slang for a basketball player, as in the video game NBA Ballers. However, this is derived from slang use of to ball as a verb meaning to play basketball. English writers everywhere occasionally make new compound words from common phrases; for example, health care is now being replaced by healthcare on both sides of the Atlantic. However, AmE has made certain words (e.g. anymore) in this fashion that are treated as phrases in BrE (e.g. any more). In compound nouns of the form <verb><noun>, sometimes AmE prefers the bare infinitive where BrE prefers the gerund. Examples include (AmE first): jump rope/skipping rope; racecar/racing car; rowboat/rowing boat; sailboat/sailing boat; file cabinet/filing cabinet; dial tone/dialling tone; drainboard/draining board. Generally AmE has a tendency to drop inflectional suffixes, thus preferring clipped forms: compare cookbook v. cookery book; Smith, age 40 v. Smith, aged 40; skim milk v. skimmed milk; dollhouse v. dolls' house; barber shop v. barber's shop. Some British English words come from French roots, while American English finds its words from other places, e.g. AmE eggplant and zucchini are aubergine and courgette in BrE, respectively. Similarly, American English has occasionally replaced more traditional English words with their Spanish counterparts. This is especially common in regions historically affected by Spanish settlement (such as the American Southwest and Florida) as well as other areas that have since experienced strong Hispanic migration (such as urban areas). Examples of these include grocery markets' preference in the U.S. for Spanish names such as cilantro and manzanilla over coriander and camomile respectively.

Pronunciation

Several pronunciation patterns contrast American and British English accents. The following lists a few common ones.

Most American accents are rhotic, preserving the historical phoneme in all contexts, while most British accents of England and Wales are non-rhotic, only preserving this sound before vowels but dropping it in all other contexts; thus, stalk and stork are homophones in British English but not in American English. American accents tend to raise the tongue whenever the phoneme (in words like ) occurs before the nasal consonants and . British accents distinguish the vowel sounds in , , and , while American accents merge the and vowels together, and about 50% of Americans additionally merge the vowel with the previous two, so for example odd, façade, and thawed can all rhyme. Many regional and informal accents of England, but few in North America, exhibit H-dropping. Words like bitter and bidder are pronounced the same in North America, but not England, due to a phenomenon called flapping involving and between vowels. British accents pronounce between vowels in other ways than Americans, including with a glottal stop or with an aspirated .

Vocabulary

The familiarity of speakers with words and phrases from different regions varies, and the difficulty of discerning an unfamiliar definition also depends on the context and the term. As expressions spread with telecommunications, they are often but not always understood as foreign to the speaker's dialect, and words from other dialects may carry connotations with regard to register, social status, origin, and intelligence.

Words and phrases with different meanings

Words such as bill and biscuit are used regularly in both AmE and BrE but can mean different things in each form. The word "bill" has several meanings, most of which are shared between AmE and BrE. However, in AmE "bill" often refers to a piece of paper money (as in a "dollar bill") which in BrE is more commonly referred to as a note. In AmE it can also refer to the visor of a cap, though this is by no means common. In AmE a biscuit (from the French "twice baked" as in biscotto) is a soft bready product that is known in BrE as a scone or a specifically hard, sweet biscuit. Meanwhile, a BrE biscuit incorporates both dessert biscuits and AmE cookies (from the Dutch 'little cake').

As chronicled by Winston Churchill, the opposite meanings of the verb to table created a misunderstanding during a meeting of the Allied forces; in BrE to table an item on an agenda means to open it up for discussion whereas in AmE, it means to remove it from discussion, or at times, to suspend or delay discussion; e.g. Let's table that topic for later. Similarly, the word moot (and moot point) in BrE means 'remains open to debate' whereas in AmE, it means 'of no practical significance', irrelevant.

The word "football" in BrE refers to association football, also known in the US as soccer. In AmE, "football" means American football. The standard AmE term "soccer", a contraction of "association (football)", is actually of British origin, derived from the ratification of different codes of football in the 19th century, and was a fairly unremarkable usage (possibly marked for class) in BrE until later; in Britain it became perceived as an Americanism. Outside North America, particularly in sports news, American (or US branches of foreign) news agencies and media companies also use "football" to mean "soccer", especially in direct quotes.

Similarly, the word "hockey" in BrE often refers to field hockey and in AmE, "hockey" usually means ice hockey.

Words with completely different meanings are relatively few; most of the time there are either (1) words with one or more shared meanings and one or more meanings unique to one variety (for example, bathroom and toilet) or (2) words the meanings of which are actually common to both BrE and AmE but that show differences in frequency, connotation or denotation (for example, smart, clever, mad).

Some differences in usage and meaning can cause confusion or embarrassment. For example, the word fanny is a slang word for vulva in BrE but means buttocks in AmE, hence the AmE phrase fanny pack is bum bag in BrE. In AmE the word pissed means being annoyed or angry whereas in BrE it is a coarse word for being drunk (in both varieties, pissed off means irritated).

Similarly, in AmE the word pants is the common word for the BrE trousers and (in AmE) knickers refers to a variety of half-length trousers (though most AmE users would use the term "shorts" rather than knickers), while the majority of BrE speakers would understand pants to mean underpants and knickers to mean female underpants.