English spelling rules

As is well-known, English spelling is very irregular. However, there are rules and generalisations that can help us avoid making unnecessary mistakes. We should all be aware of the following spelling rules:

Different spelling rules

Spelling adverbs

Most adverbs are formed through the addition of the ending -ly to an existing adjective (e.g. strangely, indifferently, supposedly). We need to be aware of the exceptions to this general pattern too (and we also need to pay attention to the fact that there are many adverbs that do not end in -ly at all, such as here and now):

  • If the adjective has more than one syllable and ends in -y, remove the -y and add -ily (e.g. scarily).

  • If the word from which the adverb is formed ends in -y, but only has one syllable, we normally add -ly, in accordance with the main rule (e.g. shyly). However, daily and gaily are exceptions.

  • If the adjective ends in -ll, only add -y (e.g. fully).

Spelling comparatives and superlatives

The second and third forms of an adjective are called comparatives and superlatives. They are regularly formed through the addition of -er and -est to the existing adjective, as in strong - stronger - strongest. However, we need to be aware of the following five exceptions to this rule:

  • If the adjective has three syllables or more, use more and most to compare them (e.g. interestingmore interestingmost interesting). The same goes for most adjectives with two syllables, for instance striking and awful.
  • If the adjective ends with a consonant followed by a -y, the -y must be changed into an -i before the ending is added (e.g. lucky – luckierluckiest).

  • If the adjective has just one syllable, contains a long vowel sound, and ends with the letter -e, we must remove the -e before adding the ending (e.g. white – whiter - whitest).

  • If the adjective has just one syllable, contains a short vowel, and ends with a single consonant letter (e.g. red), we must double the final consonant before we add the ending (e.g. red – redder reddest).

  • If the adjective ends in -l, we  normally just add the regular ending. The exception to this rule is cruel, to which an extra -l is added, so that we get cruel – crueller – cruellest.

Spelling derived words

A derived word is a word that is formed from an existing word through the addition of derivational morphology (i.e. affixes, like prefixes and suffixes).

When a derived word is formed, the original spelling sometimes stays the same, but sometimes it changes. This can be confusing, of course. The following cases ought to be remembered:

  • If a noun ends in -our, e.g. honour and labour, we must keep the u when we add  -able or -er (e.g. honourable and labourer). The u in favourite should also be kept. However, before other endings, such as -ous, the u is often lost (e.g. humorous). The u is also lost in honorary and honorific. If you use American spelling, this is not an issue at all, since there is no u in words such as honor and labor in the first place.

  • If a verb ends in -ur, add another r when you add -ence (e.g. occur becomes occurrence).

  • If a verb ends in -er, add no r when you add -ence (refer becomes reference).

  • If a verb ends in -ounce, we must remove the o when we add -iation. A frequent example of this is pronounce and pronunciation.

Spelling: Double consonants

It is often difficult to know whether a word should be spelt with a double or a single consonant. There are several problematic cases, for instance the following:

  • Some words have double consonants, even though this may not be entirely obvious. Examples of such words that are frequently misspelled include appoint (and also appointment and disappointment), address, occur, and suppress.

  • Some words do not have double consonants, even though there is a short vowel before. Pay attention to the following words: canisterbanister, and pavilion. Other words that should only have single consonants, in spite of the fact that double consonants would perhaps make more sense, are anoint, apartment, biased, and omit.

  • Some words have two sets of double consonants. It is easy to make the mistake of only doubling one of them. Examples include accommodateaggressivecommitteeembarrass, and millennium.

  • Some words have two different consonants, one of which should be doubled, while the other one should remain single. It can sometimes be difficult to know which one of them should be doubled. Likely candidates for this type of spelling mistake include appal, accumulate, and parallel.

  • Sometimes a short vowel before the consonant that should be single makes the writer's situation even more tricky. Examples of such words are the following: commemorate, desiccate, disappear, necessary, recommend, reconnoitre, titillate. Finally the Caribbean and the Mediterranean both cause problems.


It is frequently the case that writers remember one word that has a certain spelling, and think that another word that looks or sounds similar should have a certain spelling by analogy. For instance, even though accommodate has a double m following a double c, the m in  in accumulate is single; harass has only a single r even though the r in embarrass is double.

In general, many mistakes in the use of double and single consonants arise from comparisons with words that sound or look similar, or with related words. For example, many people spell inoculate with a double n, influenced by words such as innocent and innocuous.

Similarly, the number of words beginning with irr- (irregular, irritable etc.) makes the single r in iridescent harder to remember. Even trickier are words like fulfil and skilful, given the spelling of full, skill, and fill.

Spelling plurals

In English, the normal way to form a plural is to add an -s, e.g. teachers, lectures, and scholars.

If the word ends in -ch, -s, -sh, -x, -z, we should add -es instead, as in branches, masses, bushes, boxes, chintzes.

Most words that end in -f or -fe get the ending -ves (e.g. wives, calves). However, there are exceptions (e.g. beliefs, chiefs, dwarfs, gulfs, proofs, roofs).

For words that end in a vowel + y, add -s, e.g. days, boys.

If a word ends in a consonant + y, we must change the -y to -ies, e.g. babies and spies.

Words that end in -o normally just add -s, but there is a group of words that add -oes. This group includes echoes, vetoes, buffaloes, grottoes, dominoesgoeshaloes, heroes, mangoes, mosquitoes, potatoes, tomatoes, tornadoes, torpedoes, and volcanoes.

Spelling: Silent letters

Letters that are not pronounced may cause spelling problems. The silent p in psychology is an obvious example of a silent letter (but perhaps the silent p is not the main reason why psychology is difficult to spell, but rather the ch). 

Some letters are particularly likely to give rise to spelling mistakes:

  • Many words are spelled with a silent c following an s. Examples include abscess, descend (with descent), omniscient; words ending in -esce, -escent, or -escence, such as acquiesce, effervescent, and convalescent. What can be regarded as a silent c may also occur before k or q, as in acknowledge, acquainted, and acquire.

  • Silent d is easily omitted before j in adjourn, adjunct, adjudicate, and adjust (we leave it to others to debate whether it is actually the d that is silent, or the following sound [represented by the letter j] that has lost its first part).

  • The letter g precedes n in words such as align, foreign, and reign. The letter g is also sometimes followed by a silent u, as in guarantee, guard, and beleaguered.

  • Silent h is fairly common after r, as in diarrhoea (which is already difficult to spell, because of the double r and the final letter combination oea), haemorrhage (a double r increases the difficulty), rhythm. The letter c is also likely to be followed by h, as in saccharine, for example. We must also remember the h in silhouette.

Remember the t in mortgage and that debt and subtle both contain the letter b. Do not forget the i in parliament.

Sometimes writers leave out silent letters or syllables because they do not know the word's correct pronunciation. This way many people fail to pronounce the c in Arctic and Antarctic, and therefore leave it out when writing the words.

Similarly, the first r in February is often left out in both speech and writing, just like the first r in secretary. Quantitative is frequently shortened in speech to the more manageable quantitive. However, spelling this word quantitive is not acceptable, of course.

Spelling similar sounds

Some words sound as if they contain (or are related to) other familiar words. However:

  • There is no relation between cocoa and coconut.

  • Bated breath is not related to bait.

  • Corridor is not related to door (and therefore has no double o).

  • Sacrilege has the i before the e, unlike religion.

  • Abseiling has nothing to do with sailing.


Sometimes it is just part of another word that causes a mistake of this type:

  • Privilege contains no d, even though a word such as knowledge has one.

  • Attach and detach end in -ach, not -atch, unlike dispatch.

  • A protuberance is something that protrudes, but it has no r after the t.

  • Dissect has a double s, but bisect has only one.

  • Psychedelic has an e after psych, unlike psychology.

Spelling and unstressed syllables

Many English words are difficult to spell because of the way their stress pattern affects their pronunciation. When they occur in unstressed syllables, the different vowel sounds merge into a sound like "uh" or "er" (called 'schwa' in literature on pronunciation).

Since these vowels are normally reduced in this way, it can be difficult to remember which vowel should actually be used in a particular word when you use it in writing.

Examples of what we have in mind include the following:


  • It is common to confuse unstressed e and a in words such as category, desperate, separate, and grammar. It is also easy to confuse pairs such as allude/elude, and affect/effect, which have very similar pronunciations.

  • Unstressed e is sometimes erroneously written as er, especially in words such as integrate, which it is easy to confuse with words beginning with inter-.

  • The letter o can be confused with both a and e in unstressed syllables. Words that you may find difficult include corroborate (not -erate) and propaganda (not propo-).

  • In unstressed syllables, e sometimes has a short i sound. You may find it hard to remember which words spell this sound with an e (e.g. artefact, benefit, indigenous, and liquefy) and which spell it with an i (e.g. dilapidated and purify). It is easy to confuse elicit with illicit.

Spelling word endings

Word endings are easy to misspell. They are often unstressed, so the pronunciation does not give much help with the spelling. There are several pairs of suffixes that differ only in the vowel they use:


  • -ant and -ent. Words using -ant include arrogant, assistant, blatant, brilliant, defiant, flippant, malignant, and vacant. Examples of words using e are absorbent, complacent, innocent, reminiscent, independent, and transparent.

Confident and dependent, with an e, are adjectives; confidant and dependant are nouns. (But dissident and adolescent are spelled with an e, whether they are being used as nouns or as adjectives.)


  • -ance and -ancy, -ence and -ency. A noun ending in one of these suffixes usually has a corresponding adjective ending in -ant or -ent, for example dominance (dominant), expectancy (expectant), absence (absent), and decency (decent).

Where there is a pair like confident and confidant, use -ence to correspond to the adjective rather than the noun. Some verbs have a noun ending in -nce or -ncy corresponding to them, but no adjective ending in -nt. In these cases it is almost always right to use a, e.g. annoyance (annoy); but watch out for conference, existence, and interference.

  • -ary and -ery. It is very easy to confuse these two - or to spell them just as -ry. -ery is by far the less common, and is almost always used to form nouns - e.g. confectionery, jewellery. You may find this useful to remember if you tend to confuse stationery with stationary - it is the one ending in -ery that is the noun ('paper, writing materials') and the one ending in -ary that is the adjective meaning ' not moving'. -Ary can be used to form adjectives - such as complimentary - or nouns - such as secretary.

  • -able and -ible. These two endings are very often confused. The commoner ending is -able: words that finish with this include acceptable, admirable, available, comparable, indispensable, and inseparable. All new words now created with this ending are spelled -able.

-ible is the correct suffix in words such as accessible, compatible, gullible, incredible, and irresistible. Pairs of words with similar meaning but different suffixes include comprehensible and understandable, irritable and irascible.

One helpful thing to remember is that -ible is not used after vowels: there can be no doubt about which ending to use in words such as agreeable, invariable, permeable, and replaceable.

Another quick check is that if you remove -able from a word, you are usually still left with a complete word, whereas if you do the same with -ible you are not. But this is definitely a tricky area - so you had better look up the word in your dictionary.

  • -ative and -itive. The short a in the ending of words like imaginative sounds very much like the short i in definitive or sensitive, so it is easy to end up with spelling mistakes such as authorititive for authoritative. In fact -ative is much more common. It is used in words such as affirmative, alternative, demonstrative, illustrative, qualitative, and vegetative. Common words ending in -itive include acquisitive, competitive, fugitive, inquisitive, intuitive, and repetitive.
  • -ise and -ize. Most words ending in -ise can also be spelled with a final -ize: for example antagonise/antagonize, capitalise/capitalize, centralise/centralize. For some words, however, you can only use the ending -ise in British English. Some of the most common of these are advertise, advise, enterprise, exercise, improvise, revise, supervise, surprise, and televise. You can read more about -ise and -ize if you following this link:
  • If you are writing for publication, please consult your editor/publisher, since they may have very specific instructions for you to follow.

Spelling verb inflections

Some words that are already hard to spell can give further trouble when endings are added, for instance when we put a verb into the past tense. Enthral, for example, sounds as though it should be spelled with a double l but in fact has only one; but the l is doubled in enthralled and enthralling.

The i in profited and profiting is short, which makes it sound as though there should be a double t; but in fact there is only one, as in the present tense profit.

These examples may be confusing; but a few basic rules will help. When you form the past tense of a verb, or add -ing, remember the following:


  • Verbs ending in a double consonant keep it (add, added, adding, embarrass, embarrassed, embarrassing).

  • Double the final consonant if the verb has only one syllable and the vowel is short - e.g. clap, clapped, clapping.

  • Double the final consonant if the verb has two syllables and the second one is stressed - e.g. occur, occurred, occurring, acquit, acquitted, acquitting, prefer, preferred, preferring . This rule explains the confusing enthral and enthralled, fulfil and fulfilled.

  • Leave the final consonant single if the verb has two syllables and the first one is stressed - e.g. credit, credited, crediting, budget, budgeted, budgeting. This rule explains profit. It has some important exceptions: focused and biased are usually spelled with a single s in British English, and a final l is always doubled in British English.

  • Leave the final consonant single if the verb has more than two syllables and the final syllable is not stressed - e.g. benefit, benefited, benefiting, develop, developed, developing.

  • If a verb ends in e, just add d to form the past tense. Most verbs drop the e before -ing (timing, using). Ageing usually keeps the e; and singeing must keep it to distinguish it from singing.

On the use of hyphens

We know that sometimes words contain hyphens. There is considerable variation in this area (that is, not everyone agrees on the proper use of hyphens), but there are a number of cases in which hyphens are used that we must bear in mind. Also always try to be consistent, so that you do not write the same word in different ways in the same text.

At the end of a line of writing

  • If possible, put the hyphen between two parts of a compound word (eg. motor- at the end of one line and cycle at the beginning of the next one).
  • Otherwise, put the hyphen before a suffix (understand -ably, instead of understa -ndably) or after a prefix (mono- transitive, instead of monot- -ransitive).
  • Words that are not compounds and which do not contain affixes are normally not long enough to have to be divided at the end of a line.

In compounds

Generally speaking, compounds can be written in three different ways in English, namely as one word, as two words with a space between them, or with a hyphen between the first and the second part of the word. In many cases, there is variation among writers, and writing conventions change over time, so always consult a recent and trusted dictionary when in doubt. However, the following general rules and advice should be useful:

Compound adjectives are often (but not always) written with a hyphen. A compound adjective is typically an adjective that consists of an adjective + a participle (e.g. long-lasting and short-natured), a noun + a participle (thought-provoking and data-driven), or a noun + and adjective (camera-ready, lead-free).

It is extra important to use a hyphen when not using one could lead to ambiguity. For instance, we should not write ten year old children if we mean ten-year-old children, since ten year old children could equally well refer to ten children that are one year old (i.e. ten year-old children).

Generally speaking, compound premodifying adjectives, that is, adjectives that precede and modify the head of a noun phrase, are more often written with a hyphen than compound adjectives functioning as predicatives. This is especially important to remember when the compound adjective contains the adverb well. For example, even though we could very well write as in (1), we have to use the hyphen in (2):

(1) I find this paper well written.

(2) This is really a well-written paper.

Similarly, we have to use hyphens if a premodifying adjective is formed from a phrase (3), even though we may leave out the hyphen when such a compound adjective functions as predicative (4):

(3) A new state-of-the-art laboratory on Deeside marks a big step ahead in Wales' drive for economic renewal and green jobs.

(4) This document is part of a series of reviews of the state of the art in cognitive systems.


Compound numbers less than 100 are spellt with a hyphen (e.g. seventy-six, thirty-five). 


Phrasal verbs

(5) Long queues started to build up at these security checkpoints.

(6) There was a build-up of fluid in the inner ear, and the doctors drained the fluid out so the child could hear.


After a prefix

We insert a hyphen between a prefix and a number or a proper noun (name):

(7) This is a pre-2004 phenomenon.

(8) This would reduce the risk of the further deterioration of Iraq into a post-Yugoslavia type of situation.


We also include a hyphen in order to avoid words getting mixed up, so, for instance, we write re-cover, if we do not mean recover, as in (9):

(9) I would like to know how to re-cover dining-room chairs.


It is (or used to be) common practice to insert a hyphen between a prefix ending in a vowel and a word starting with a vowel, as in (10), but this use appears to be losing ground, so we also frequently find such words written as one word without a hyphen, as in (11):

(10) Nato and Russia have made a historic agreement to co-operate over the creation of a missile defence shield protecting more than one billion people in a move aimed at bolstering the “reset” in relations between Moscow and the west.

(11) Although the duty to cooperate would render it more difficult for local authorities to refuse a transfer outright, it did not override their discretion when deciding whether this would be compatible with other of their statutory duties or whether they could fulfil the terms of an offender's licence conditions.


There are also a number of prefixes that are always supposed to be followed by a hyphen, for instance all-, cross-, ex-, self-, half-, and anti--, as in (12) to (17):

(12) In principle this could be done by an all-knowing central planner.

(13) Cross-Cultural Research (CCR) publishes peer-reviewed articles that describe cross-cultural and comparative studies in all human sciences.

(14) After a year or so, my friend and ex-colleague John. Murray VII offered help again.

(15) Self-esteem has to do with how one sees and experiences oneself.

(16) There is no way anyone in attendance left this show thinking it was half-hearted

(17) To illustrate what types of behaviour are anti-social, below are examples of ASB.


And please remember the practice of spelling premodifying compounds with hyphens, as illustrated in some of the examples above.

For more useful advice on spelling, please follow this link:

It should be noted that this AWELU page on spelling was inspired by a previous version of the web site to which this link refers.