American and British English spelling differences

Doubled consonants

Doubled in British English

The final consonant of an English word is sometimes doubled in both American and British spelling when adding a suffix beginning with a vowel, for example strip/stripped, which prevents confusion with stripe/striped and shows the difference in pronunciation (see digraph). Generally, this occurs only when the word's final syllable is stressed and when it also ends with a single vowel followed by a single consonant. In British English, however, a final -l is often doubled even when the final syllable is unstressed.^[88] This exception is no longer usual in American English, apparently because of Noah Webster.^[89] The -ll- spellings are nevertheless still regarded as acceptable variants by both Merriam-Webster Collegiate and American Heritage dictionaries.

The British English doubling is required for all inflections (-ed, -ing, -er, -est) and for the noun suffixes -er and -or. Therefore, British English usage is cancelled, counsellor, cruellest, modelling, quarrelled, signalling, traveller, and travelling. Americans usually use canceled, counselor, cruelest, modeling, quarreled, signaling, traveler, and traveling.
- The word parallel keeps a single -l- in British English, as in American English (paralleling, unparalleled), to avoid the unappealing cluster -llell-.
- Words with two vowels before a final l are also spelled with -ll- in British English before a suffix when the first vowel either acts as a consonant (equalling and initialled; in the United States, equaling or initialed), or belongs to a separate syllable (British fu•el•ling and di•alled; American fu•el•ing and di•aled).
  - British woollen is a further exception due to the double vowel (American: woolen). Also, wooly is accepted in American English, though woolly dominates in both systems.^[90]
Endings -ize/-ise, -ism, -ist, -ish usually do not double the l in British English; for example, normalise, dualism, novelist, and devilish.
- Exceptions: tranquillise; duellist, medallist, panellist, and sometimes triallist in British English.
For -ous, British English has a single l in scandalous and perilous, but the "ll" in marvellous and libellous.
For -ee, British English has libellee.
For -age, British English has pupillage but vassalage.
American English sometimes has an unstressed -ll-, as in the UK, in some words where the root has -l. These are cases where the alteration occurs in the source language, which was often Latin. (Examples: bimetallism, cancellation, chancellor, crystallize, excellent, tonsillitis, and raillery.)
All forms of English have compelled, excelling, propelled, rebelling (notice the stress difference); revealing, fooling (note the double vowel before the l); and hurling (consonant before the l).
Canadian and Australian English largely follow British usage.^[88]

Among consonants other than l, practice varies for some words, such as where the final syllable has secondary stress or an unreduced vowel. In the United States, the spellings kidnaped and worshiped, which were introduced by the Chicago Tribune in the 1920s,^[91] are common. Kidnapped and worshipped, the only standard British spellings.

Miscellaneous:

British calliper or caliper; American caliper.
British jewellery; American jewelry. The standard pronunciations (/ˈdʒuːᵊlri/)^[92] do not reflect this difference. According to Fowler, jewelry used to be the "rhetorical and poetic" spelling in the UK. Canada has both, but jewellery is more often used. Likewise, the Commonwealth (including Canada) has jeweller and the United States has jeweler for a jewel(le)ry retailer.

Doubled in American English

Conversely, there are words where British writers prefer a single l and Americans usually use a double l. In American usage, the spelling of words is usually not changed when they form the main part (not prefix or suffix) of other words, especially in newly formed words and in words whose main part is in common use. Words exhibiting this spelling difference include wil(l)ful, skil(l)ful, thral(l)dom, appal(l), fulfil(l), fulfil(l)ment, enrol(l)ment, instal(l)ment. These words have monosyllabic cognates always written with -ll: will, skill, thrall, pall, fill, roll, stall, still. Cases where a single l nevertheless occurs in both American and British English include null→annul, annulment; till→until (although some prefer "til" to reflect the single L in "until", occasionally using an apostrophe ['til]); and others where the connection is not transparent or the monosyllabic cognate is not in common use in American English (e.g. null is used mainly as a technical term in law, mathematics, and computer science).

In the UK, ll is used occasionally in distil(l), instil(l), enrol(l), and enthral(l)ment, and often in enthral(l), all of which are always spelled this way in American usage. The former British spellings instal, fulness, and dulness are now quite rare.^[93] The Scottish tolbooth is cognate with toll booth, but it has a specific distinct sense.

In both American and British usages, words normally spelled -ll usually drop the second l when used as prefixes or suffixes, for example full→useful, handful; all→almighty, altogether; well→welfare, welcome; chill→chilblain.

The British fulfil and American fulfill are never fullfill or fullfil.

Dr Johnson wavered on this issue. His dictionary of 1755 lemmatises distil and instill, downhil and uphill.^[94]

Dropped e

British English sometimes keeps silent e when adding suffixes where American English does not. Generally speaking, British English drops it in only some cases in which it is unnecessary to indicate pronunciation whereas American English only uses it where necessary.

British prefers ageing^[95], American usually aging (compare raging, ageism). For the noun or verb "route", British English often uses routeing;^[96], but in America routing is used. (The military term rout forms routing everywhere.) However, all of these word form "router", whether used in the context of carpentry, data communications, or military. (e.g. "Attacus was the router of the Huns at ....")

Both forms of English retain the silent e in the words dyeing, singeing, and swingeing^[97] (in the sense of dye, singe, and swinge), to distinguish from dying, singing, swinging (in the sense of die, sing, and swing). In contrast, both bathe and the British verb bath both form bathing. Both forms of English vary for tinge and twinge; both prefer cringing, hinging, lunging, syringing.

Before -able, British English prefers likeable, liveable, rateable, saleable, sizeable, unshakeable^[98], where American practice prefers to drop the -e; but both British and American English prefer breathable, curable, datable, lovable, movable, notable, provable, quotable, scalable, solvable, usable^[98], and those where the root is polysyllabic, like believable or decidable. Both forms of the language retain the silent e when it is necessary to preserve a soft c, ch, or g, such as in traceable, cacheable, changeable; both usually retain the "e" after -dge, as in knowledgeable, unbridgeable, and unabridgeable. ("These rights are unabridgeable.")
Both abridgment and the more regular abridgement are current in America, only the latter in the UK.^[99] Similarly for the word lodg(e)ment. Both judgment and judgement are in use interchangeably everywhere, although the former prevails in America and the latter prevails in the UK^[100] except in the practice of law, where judgment is standard. The similar situation holds for abridgment and acknowledgment. Both forms of English prefer fledgling to fledgeling, but ridgeling to ridgling.
The word "blue" always drops the "e" when forming "bluish".