Guide to

English Spelling Rules

Basics of British and American spelling with a minimum of effort

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Noun Plural Formation	Troublesome Suffixes and Endings
Dropping of Letters	General Observations
Doubling of Letters	One Word or More?
Troublesome Prefixes	Words Commonly Confused

Noun Plural Formation

Spelling Rule	Examples	Exceptions to the Rule
To form the plural of most nouns, simply add -s	a cat > two cats one dog > six dogs	Surviving Old English plural forms: deer > deer sheep > sheep ox > oxen man > men woman > women child > children brother (in a religious sense) > brethren foot > feet tooth > teeth A few compound nouns: passer-by > passers-by mother-in-law > mothers-in-law Some foreign words that are not yet fully naturalized: chateau > chateaux crisis > crises formula > formulae index > indices stimulus > stimuli Plural forms of metric abbreviations: 100 km (kilometres) 60 g (grams) 2.5 l (litres) In abbreviations of non-metric measurements, the s-plural is optional: 60 lb or 60 lbs
To form the plural of nouns ending in *s, sh, ss, z, x or ch,* add -es to facilitate pronunciation	gas > gases dish > dishes boss > bosses box > boxes watch > watches
To form the plural of nouns ending in y after a consonant, remove the y and then add -ies	lady > ladies baby > babies strawberry > strawberries laboratory > laboratories	lay-by > lay-bys BrE stand-by > stand-bys Family names also retain any final y when pluralized: Mr. & Mrs. Brady > The Bradys
To form the plural of a number of long established English nouns ending in f or fe (but not ff or ffe!) remove the f or fe and then add -ves	half > halves leaf > leaves life > lives knife > knives	Most other nouns ending in f or fe simply add -s as usual, but there are a few cases in which the -ves plural is optional: belief > beliefs chief > chiefs safe > safes handkerchief > handkerchiefs BrE also handkerchieves Caution is advised so when in doubt please consult a dictionary.
To form the plural of imported nouns ending in o and long established in English, add -es	cargo > cargoes domino > dominoes echo > echoes embargo > embargoes hero > heroes potato > potatoes tomato > tomatoes tornado > tornadoes torpedo > torpedoes veto > vetoes	For less naturalized nouns ending in o, add -s only: kilo > kilos piano > pianos kimono > kimonos radio > radios In a few cases the -es plural formation is optional. When in doubt, consult your dictionary! archipelago > archipelagos or archipelagoes fiasco > fiascos or fiascoes halo > halos or haloes mango > mangos or mangoes

Dropping of Letters

Spelling Rule	Examples	Exceptions to the Rule
A final silent e is usually dropped before you add any suffix beginning with a vowel	-able It is not so easy to predict when a final e should be dropped before adding the suffix -able. Generally speaking, this is more common in American English. In some cases it is optional, e.g. likable or likeable	Words ending in -ce and -ge usually retain their final e to help clarify the soft pronunciation of a preceding consonantal sound: notice > noticeable peace > peaceable knowledge > knowledgeable manage > manageable The final e is also retained for words ending in -ee: agree > agreeable foresee > foreseeable
	-age store > storage	acre > acreage mile > mileage Note also that linage and lineage are entirely different words.
	-ed clone > cloned
	-est cute > cutest
	-ing dive > diving write > writing	You must retain the final e when it is needed to distinguish meaning: dye > dyeing (cf. die > dying) singe > singeing (cf. sing > singing) Sometimes the e is kept to clarify the soft pronunciation of a preceding consonantal sound (e.g. ageing). American English, however, seems to pay less attention to this: BrE to age > ageing AmE to age > aging The final e is also kept for words ending in -ee, -oe, or -ye: flee > fleeing canoe > canoeing eye > eyeing
	-ous fame > famous pore > porous	Words ending in -ge keep their final e to clarify the soft pronunciation of a preceding consonantal sound: advantage > advantageous courage > courageous In the case of words ending in -ce this final e becomes an i: grace > gracious space > spacious
	-y ice > icy bone > bony	The final e is not dropped before adding the y-suffix if the preceding letter is u: glue > gluey (comparative: gluier) Other important exceptions: price > pricey space > spacey Remember too that holy and holey are very different words!

Doubling of Letters

Spelling Rule	Examples	Exceptions to the Rule
When a suffix beginning with a vowel is added to a stressed syllable ending in a single consonant that is preceded by a single vowel, the consonant *is usually doubled*	-able control > controllable -ed admit > admitted stop > stopped In the following two cases the stress in the final syllable is secondary: kidnap > kidnapped program > programmed -er big > bigger -ing begin > beginning refer > referring -ish red > reddish	In British English, a final letter l following a single vowel is doubled even if the syllable is unstressed: travel > travelled American English not only adheres to the usual rule requiring the final syllable to be stressed before doubling, it doubles the final l in all forms of the verb, thereby eliminating this particular spelling headache altogether: AmE enroll > enrolled fulfill > fulfilled BrE enrol > enrolled fulfil > fulfilled
		Consult a dictionary before doubling a final s to form noun plurals, especially in monosyllabic words: gas > gases bus > buses (but AmE busses) A final z is always doubled: fez > fezzes quiz > quizzes In words of more than one syllable, both British and American English follow the usual stress rule when adding -es to form the third person singular of the present tense: focus > focuses nonplus > nonplusses In British English (as in the case involving a final l above), a stressed syllable is not a prerequisite for doubling the s before -ed and -ing to form past tenses and gerunds. So BrE grants you the option of either focussed or focused and focussing or focusing. AmE on the other hand, prefers the latter variants focused and focusing, in line with the general rule requiring a stressed syllable for consonant doubling.
		Instead of doubling a final consonant c (which only occurs in unstressed syllables), it becomes ck before the addition of a suffix: traffic > trafficking frolic > frolicking
		The consonants h, w, x and y are never doubled (e.g. affix > affixing), and neither are silent consonants found in words of foreign origin: crochet > crocheting ricochet > ricocheting

Troublesome Prefixes

Spelling Rule	Examples	Exceptions to the Rule
ante- or anti- ? Choose the prefix ante- if your word means before or ahead, and anti- if it means opposite or against	ante- does not usually have to be followed by a hyphen: antecedent antedate antenatal anteroom
	Even with anti- most words require no hyphenation: antibiotic anticlockwise anticyclone antidepressant antifreeze anti- is always followed by a hyphen before an i or a capital letter: anti-inflammatory anti-French	There are many other anti- words that are hyphenated by convention, according to personal preference, or to avoid a vowel clash: anti-aircraft fire anti-establishment anti-government anti-gravity anti-personnel mines Whenever you're in doubt, consult a good dictionary!
fore- or for- ? Choose the prefix fore- if your word means before or ahead; otherwise you need for-	Forecast, forefather, foresrunner, foreshadow, foresight, forestall, foretaste, foretell, forewarn, etc. Forbid, forfeit, forget, forgive, forgo, forlorn, forsake, forswear, etc.

Troublesome Suffixes and Endings

Spelling Rule	Examples	Exceptions to the Rule
-able or -ible ? The suffix -able is far more common than -ible	Most roots, including all modern ones, add -able: drink > undrinkable read > readable wash > washable	You'll find -ible only in a few old words that are derived directly from(or modeled on) Latin: flex > flexible comprehend > comprehensible respond > responsible Lat. "edere" (to eat) > edible
-ance or -ence ? -ant or -ent ? Here we present a few useful rules, but since they are not 100% reliable, when in doubt consult a dictionary!	-ance is always added to a hard c or g: elegance significance If the preceding c or g is soft choose -ence: innocence intelligence	Note the unique spellings of allegiance and vengeance.
	If other forms of the word end in an a-suffix, then your choice is likely to be -ance and -ant: dominate > dominance ignoramus > ignorant vigilante > vigilance	Irregularity: violate > violence
	Verbs ending in -ear, -ure and -y have noun forms ending in -ance: appear > appearance endure > endurance defy > defiance
	Verbs ending in -ere will have noun forms ending in -ence: interfere > interference	Irregularity: persevere > perseverance
	The core syllables -cid-, -fid-, -sid-, -vid-, -flu-, -qu- and -sist- are usually followed by -ence: incidence confidence subsidence evidence influence consequence insistence	Notable exceptions: assistance resistance
	To form nouns from verbs ending in a stressed -er or -ur, add -ence: confer > conference concur > concurrence Note for "concurrence" that typical doubling of the end consonant in a stressed syllable before adding a suffix beginning with a vowel.
	To form nouns from verbs ending in an unstressed -er, add -ance: utter > utterance hinder > hindrance	Irregularity: differ > difference
-ce or -se ? During centuries of separation from Britain, American English retained the original -se ending in certain words borrowed from French, while British English modified it to -ce	AmE defense offense pretense vise (a tool) BrE defence offence pretence vice	Note that even in British English any related adjectives have to be spelt with an s: defence > defensive offence > offensive
	Along the lines of advice vs. advise, British English sometimes utilizes the -ce and -se suffixes to help distinguish a noun from a verb: BrE a licence / to license some practice / to practise	American English, which tends to lay emphasis on simplified spelling, sees no reason to make this kind of subtle distinction: AmE a license / to license some practice / to practice
-cede or -ceed ? The ending -cede is far more common than -ceed	concede precede recede	You'll find -ceed only in: exceed proceed succeed Note the unique spelling of supersede.
-ch or -tch ? Choose -ch if it is to be preceded by either a consonant or two vowels, but if it is to be preceded by a single vowel, you need -tch	filch bench church
	approach touch coach	One exception to the rule requiring a -ch ending after two vowels is the letter h: aitch
	catch fetch watch	A handful of very common words are exceptions to the rule requiring -tch after a single vowel, so you should make a point of memorizing them: attach detach enrich much rich sandwich spinach such which
-ction or -xion ? The ending -ction is far more common than -xion	reaction reduction	-xion is found only in a few words: complexion crucifixion effluxion flexion fluxion prefixion retroflexion transfixion
	connection deflection inflection reflection	In BrE only, you may come across the following variants: connexion deflexion inflexion reflexion
-er or -or ? The ending -er is far more common than -or	-er is added to most verbs (and certainly all modern ones) for someone or something performing an activity: player baker singer	A few -er nouns are created from other nouns or from adjectives foreign > foreigner law > lawyer prison > prisoner
	Note the following words: adapter (a person who adapts) adviser caster conjurer conveyer resister (a person who resists).	Especially in British English, an adaptor is a device to make two pieces of (usually electrical)equipment compatible, as well as being an accepted variant of adapter (someone who adapts something); the variant advisor is not uncommon but is still rather controversial; the variants castor, conjuror and conveyor are quite correct; and a resistor is an electronic component.
	-or is found in words of French or classical origin: mayor donor Many end in -ator, -itor, -ctor, -essor and -utor: curator auditor director professor tutor
-ize or -ise ? The verbal suffix -ize is far more common than -ise	criticize demoralize realize vandalize	In Britain, under the influence of neighboring French, the -ise ending remains a widespread alternative, but if chosen it should be used consistently throughout the same piece of writing: criticise demoralise realise vandalise Memorize these common verbs, which are always spelt with -ise: advertise chastise despise disguise franchise merchandise surmise Note too those verbs reliably ending in -cise, -prise and -vise: exercise surprise advise
-our or -or ? Words of primarily French origin ending in -our in British English end in a simplified -or in American English	BrE colour favour honour AmE color favor honor	British English also often uses -or: error terror stupor British English also drops the u in -our before the addition of a suffix to certain words: vapour > vaporize honour > honorific; honorary American English still prefers glamour to glamor. Contrary to widespread belief, this term does not emanate from French but rather surprisingly from a Scottish alteration of the English word grammar. In the Middle Ages the casting of spells was apparently associated with people of learning.
-re or -er ? While British English retains the chic -re ending in words of French origin, American English generally prefers the anglicized form -er	BrE centre metre theatre AmE center meter theater	Despite its efforts to simplify modern spelling, American English still plays host to the -re ending in some words, especially when it is needed to indicate a preceding hard consonant. This applies to the following words with a stem ending in the letter c: acre massacre mediocre But note also cadre and ogre.
-yse or -yze ? The verbal suffix -yse is British and -yze is American	BrE analyse paralyse AmE analyze paralyze

General Observations

Spelling Rule	Examples	Exceptions to the Rule
-ae/oe or -e ? ae (æ) and oe (œ) in words of Greek or Latin origin are retained in British English and replaced with a simple e in American English	BrE archaeology gynaecology haemoglobin diarrhoea foetus oesophagus AmE archeology gynecology hemoglobin diarrhea fetus esophagus	The degree to which British English is willing to give up these rather cumbersome Latin and Greek spellings appears to depend on the extent to which a term is truly in the public domain and not just confined to professionals and academics. For example, the form encyclopedia is now far more common than the traditional encyclopaedia.
ie or ei ? In the case of 'ee' /i:/ sounds, i goes before e except after c	No preceding c hence ie: believe chief siege After c hence ei: ceiling receive deceit	Notorious deviants from this rule: caffeine protein inveigle seize weird And beware of words that have varied pronunciation: either neither heinous Some common names: Keith, Sheila, Neil, Madeira Latin words like species
q_ ? q is almost invariably followed by u	quack quality queen question quiz quote	Acronyms and non-English words: Qantas (Australian Airline) Al Qaeda (Islamist terror franchise) Qatar (Gulf state)

One Word or More?

Options	Clarification
alright or all right ?	all right is still widely regarded as the correct form
already or all ready ?	"Kids, it's already 8 o'clock. Are you all ready to leave for school?"
altogether or all together ?	"There are altogether four occasions per year when the entire family are all together."
anyone or any one ?	"Anyone can use the library and borrow any one of 10,000 books."
cannot or can not ?	cannot is the correct form in British English, while can not is generally preferred in American English. Even BrE lets you use can not for emphasis: "She cannot speak any oriental languages, but when it comes to African languages she can not only speak Swahili but Shona and Zulu as well."
-ever or ever ?	ever is only separated from a wh-word for the sake of emphasis: "You can go wherever you like and do whatever you want!" "Where ever have you been and what ever have you been up to?"
everyone or every one ?	Everyone is the same as "everybody" and applies to people only. Every one means 'each single one' and applies to both people and things: "Everyone ate at the restaurant and every one of them ordered spaghetti."
inasmuch as or in as much as ?	Both forms are correct but inasmuch as now seems to be more common: "He is responsible for the accident inasmuch as he failed to prevent it."
insofar as or in so far as ?	Both forms are correct but in so far as now seems to be more common: "She appreciated him in so far as he was always very positive."
into or in to ?	These two mean slightly different things and are often confused in modern English. Into is a preposition: "They got into their car." With in to we have the combination of an adverb followed by a preposition: "She joined her friend at the hotel and accompanied her in to dinner."
maybe or may be ?	"Maybe he'll stay a while longer in Chicago, although he may be moviing down to Dallas next spring."
no-one or no one ?	Nowadays both these forms are considered correct, but purists may like to see the following two distinct usages reflected in their spelling: "No-one has so far been charged with causing the accident because no one person was to blame."
onto or on to ?	It seems that onto does not enjoy the same dominant status as into above. So in modern-day English, onto and on to are both regarded as correct prepositional forms. In cases where the on is an adverb, however, on to must be used: "When he finally got onto the highway, he went on to LA."
sometime or some time ?	"She'll do it sometime when she gets some time."