Differences in pronunciation between British English and American English are numerous though nearly all the British peculiarities have their counterpart in one section or another of the United States. King’s English gives a broad [a:] sound to words like bath and dance, but so do several New England varieties. The flat [æ] sound in bath and dance is common in General American. The sound given by most Englishmen to words containing so-called “short” [o] (pot, lot)is more like a shortening of the [a:] in father in American English. The diphthong [ou] exists in both languages, but in English pronunciation the sound is much narrower [әu].
Differences in the pronunciation of individual words are quite numerous, ['∫edju:l], [kla:k], ['da:bi] are the British pronunciation of schedule, clerk, derby, while Americans use ['skedju:l), [klә:k], ['dә:bi]. The British Army pronounces lieutenant [lәf'tenәnt] while Americans generally say [lju:'tenәnt], though a pronunciation similar to American is used for the rank in the British Navy.
The primary difference between English and American is in the rhythm and intonation of speech.
Vocabulary differences between British and American usage as well as differences in shade of meaning in the common stock of words are also numerous. In Britain an information bureau is an inquiry office,a ticket agent is a booking clerk;a freight car is goods-waggon. Dessert in Britain means fruit, and you must use sweet if you want a dessert, while if you ask for biscuits you will get crackers.The British equivalent of a cigar-store is a tobacconist’s.The British billion is American trillion,and milliard should be used to signify American billion.
There also are differences between US and British usage in spelling. So many words ending in -bre, -tre, in Britain (centre, theatre, metre, fibre)are spelled -er in the U.S. (center, theater, meter, fiber). Words ending in -our in Britain (honour, colour, vigour, labour)are usually spelled -or in the U.S. (honor, color, vigor, labor).Most verbs ending in -ize or -ise are spelled -ize in the U.S. with the exception of a small number of verbs like advertise, devise and surprise having different origin.
The words ending in -ce or -se are spelled in American use -se: defense, offense,while in British use they are more often spelled defence, offence.In British use, words of more than one syllable ending in -l and forming derivative double the -l before a vowel (travelled, paralelled, quarelled, medallist, woollen, woolly, councillor, etc.), whereas in American use –lis not doubled in these words.
There also is a tendency of simplifying the spelling of some words containing the mute gh, so one comes across plow (for British, plough) and thru (for British, through), the latter being used mostly in advertisements, business letters and notices. For advertising purposes night also comes to be occasionally spelled as nite.