Services publics et Approvisionnement Canada
Symbole du gouvernement du Canada

Avis important

L’outil The Canadian Style a été archivé et ne sera plus mis à jour jusqu’à son retrait définitif.

Pour obtenir notre contenu le plus à jour, veuillez consulter Writing Tips Plus, un outil combinant le contenu des outils Writing Tips et The Canadian Style. N’oubliez pas de modifier vos favoris!

Rechercher dans

3 Spelling

3.01 Introduction

Spelling poses a major problem in English because it is not phonetic and because the rules that can be formulated nearly always have significant exceptions. In addition, there are hundreds of words that have variant spellings in different parts of the English-speaking world, the principal cleavage being between the United Kingdom and the United States. Partly as a result of our historical links with Britain and our proximity to the United States, Canadian spelling has tended to waver between the forms used in these two countries, so that, to this day, there is no clearly established Canadian standard.

While a list of words that have variant spellings in British and American practice would run into the hundreds and still not be exhaustive, the great majority of them fall into a few well-defined classes, as listed below. The British variants are given in the left-hand column, the American in the right-hand column:

  • verbs ending in ise/ize and their derived forms:

    British American
    civilise, civilisation civilize, civilization
    organise, organisation organize, organization
    specialise, specialisation specialize, specialization

  • nouns ending in our/or:

    British American
    colour, honour, favour color, honor, favor

  • nouns ending in re/er:

    British American
    centre, fibre, theatre center, fiber, theater

  • verbs with single l/double l and their derivatives:

    British American
    instil instill
    fulfil, fulfilment fulfill, fulfillment
    enrol, enrolment enroll, enrollment

  • nouns in ce/se1:

    British American
    defence, offence, pretence defense, offense, pretense

  • double l/single l in the past tense of verbs:

    British American
    counselled, labelled counseled, labeled
    travelled traveled

  • treatment of the digraphs ae and oe in words derived from Greek and Latin:

    British American
    anaemia, encyclopaedia anemia, encyclopedia
    diarrhoea, oecumenical diarrhea, ecumenical


  • Back to the note1 British spelling also makes a distinction between certain noun and verb forms that is not maintained in American spelling. Thus, British licence (noun), license (verb) and practice (noun), practise (verb); American license and practice for both forms.

The recommended spelling authority is a reliable Canadian dictionary such as the Canadian Oxford or Gage Canadian Dictionary. It is important to choose one and use it consistently. Both publications are based on research into Canadian usage, contain specifically Canadian terms and reflect the usage of most federal government departments and agencies more closely than do American or British dictionaries. When they list two spellings for a word in the same entry, choose the one entered first. When two spellings are given separate entries, choose the primary spelling, which is the one followed by the definition (the variant simply refers the reader to the primary entry). For scientific and technical words not in Gage or the Canadian Oxford, check Webster’s Third New International Dictionary.

In light of these recommendations, use the following variant spellings: endings in ize, ization, our, re, single l (as in instil) and ce; single l in words such as enrolment; ll in travelled, etc.; and e for digraphs (exceptions: aesthetic and onomatopoeic).


Respect the official spelling of names of U.S. institutions, e.g. Department of Defense, Center for Disease Control.

The rules and lists of words given in this chapter are intended to supplement, not replace the use of the spelling authority you choose. The important point with respect to spelling is to be consistent in your written work unless a good reason exists for using variant or archaic spellings.

3.02 Spell checking

Spell-checking functions are now included in word-processing programs for use with computers. They can help you eliminate, at the proofreading stage, most of the spelling and typographical errors in a document. Especially useful are the "search" feature, which can instantly locate a specific combination of letters, and the "search-and-replace" feature, which can find all instances of a misspelled word or variant spelling and replace them with the correct or preferred form.

Spell-checking programs do have the following drawbacks:

  • They cannot detect omissions of words.
  • They do not flag correctly spelled words that are incorrect in the specific context. Thus the sentence

    Ewe bake two manly arrows.

    would be approved by a spell checker for a sentence that should read

    You make too many errors.

  • Unless they are part of a larger grammar-checking utility, they do not identify words that are grammatically wrong. Thus the sentence

    He do not understands.

    would not be flagged.

  • They may not respect the spelling preferences of your organization or your clients. In this case, you can usually modify the content of the spell-checker dictionary.
  • The search-and-replace feature can result in misspellings that have to be reversed manually. For example, you may have decided to use the spelling honour instead of honor, the variant listed in American spell-checker dictionaries. Instructing the spell checker to make a universal change will affect even correctly spelled words such as honorarium, honorific and honorary as well as words placed in quotes or followed by [sic]. To avoid the error, give the command


    instead of just


    A variation of this command is required to cover specific occurrences such as honor followed by a period.

3.03 Frequently misspelled words

The following is a list of words that are often misspelled. The letters that are usually the object of the errors—through inversion, omission, doubling, addition or substitution—are in boldface:

  • abhor
  • abysmal
  • accommodate
  • acquaintance
  • aggressive
  • all right
  • anomalous
  • appellant
  • arctic
  • argument
  • attorney
  • awkward
  • battalion
  • calendar
  • canister
  • Caribbean
  • cartilage
  • census
  • Chile (the country)
  • chlorophyll
  • coherent, coherence
  • Colombia (the country)
  • commitment
  • comparative
  • concomitant
  • connection
  • consensus
  • consistent, consistency
  • corollary
  • correspondence
  • crystallographic
  • Dene (no accents in English)
  • descend
  • desiccate
  • develop
  • diarrhea
  • diphtheria
  • disappoint
  • discernible
  • domain (not domaine)
  • dysentery
  • ecstasy
  • embarrass
  • exaggerate
  • excerpt
  • exhilarate
  • existent, existence
  • exonerate
  • exorbitant (not exhorbitant)
  • Filipino
  • focus
  • foreseen
  • gauge
  • genealogy
  • grammar
  • guerrilla
  • harass
  • hemorrhage
  • hereditary
  • histogram
  • honorary
  • hypocrisy
  • hypothesis
  • independent, independence
  • indispensable
  • infinitesimal
  • inoculate
  • inscribe
  • insistent, insistence
  • Inuit
  • Inuk
  • iridescent
  • irrelevant
  • laboratory
  • liaison
  • lightning
  • liquefy
  • marshal
  • measure
  • medicine
  • memento
  • Métis
  • minuscule
  • Mississippi
  • misspell
  • moccasin
  • Morocco
  • naphtha
  • negotiation
  • nickel
  • occasional
  • occurrence
  • ophthalmology
  • paraffin
  • parallel
  • pastime
  • perinatal
  • permissible
  • Philippines
  • polyethylene
  • polystyrene
  • polyurethane
  • possession
  • precede
  • preferential
  • privilege
  • proceed
  • pronunciation
  • ptomaine
  • quadriplegia
  • rarefy
  • recede
  • recommendation
  • reminiscent
  • resistant, resistance
  • responsible
  • rheumatism
  • rhythm
  • sacrilegious
  • separate
  • siege
  • soybean
  • spatial
  • stochastic
  • supersede
  • tariff
  • tendency
  • thorough
  • threshold
  • until
  • weird
  • withhold
  • written

3.04 SI/metric units

Preferred spellings of terms have been established in National Standard of Canada CAN/CSA-Z234.1-89 for a number of SI/metric units and prefixes: deca (not deka), gram (not gramme), litre (not liter) and tonne or metric ton (not metric tonne).

In two cases the final vowel of a unit prefix is omitted: megohm and kilohm. In other cases where the unit name begins with a vowel, both vowels are retained.

Note that meter is the spelling for a measuring device, while metre is the unit of length.

Note also that the singular and plural of the following unit names are identical: hertz, lux and siemens.

3.05 Homonyms and similar-sounding words

Many words are misspelled because they are confused with similar-sounding and similarly spelled words which, in fact, have a different meaning. In the following list of word pairs (and one group of three), information is given in parentheses to indicate which spelling should be used in a particular context:

  • affect (influence)
    • effect (verb: bring about, result in; noun: consequence, impact)
  • allusion (reference)
    • illusion (misleading appearance)
  • all ready (prepared)
    • already (previously)
  • all together (together in a group)
    • altogether (entirely)
  • ascent (climb)
    • assent (agreement)
  • bloc (group of persons, companies or nations)
    • block (group of things; obstruct; solid piece, etc.)
  • born (of birth)
    • borne (carried)
  • breach (gap; violation)
    • breech (lower part)
  • broach (pointed tool or rod; begin to talk about)
    • brooch (type of jewellery)
  • canvas (cloth)
    • canvass (solicit)
  • capital (city; very significant)
    • capitol (government building in U.S.A.)
  • carat (unit of mass for precious stones)
    • caret (proofreader’s mark)
    • karat (unit used to specify proportion of gold in alloy)
  • cast (actors; verb meanings)
    • caste (exclusive social class)
  • censor (check the morality or acceptability of; person who does this)
    • censure (criticize, blame; criticism)
  • chord (music; geometry; engineering)
    • cord (other uses)
  • complement (complete; that which completes)
    • compliment (praise)
  • councillor (member of a council)
    • counsellor (adviser; lawyer)
  • dependant (noun)
    • dependent (adjective)
  • discreet (prudent, tactful)
    • discrete (distinct, separate)
  • dyeing (colouring)
    • dying (approaching death)
  • elicit (draw forth)
    • illicit (unlawful)
  • envelop (verb)
    • envelope (noun)
  • faze (disturb)
    • phase (stage, period)
  • flair (talent)
    • flare (flame, light)
  • forbear (hold back)
    • forebear (ancestor)
  • foreword (preface)
    • forward (ahead)
  • hoard (save up)
    • horde (crowd)
  • immanent (inherent)
    • imminent (about to occur)
  • inequity (unfairness)
    • iniquity (sin)
  • its (belonging to it)
    • it’s (it is)
  • loath (adjective)
    • loathe (verb)
  • loose (set free; untight, etc.)
    • lose (mislay; forfeit)
  • mantel (shelf above fireplace)
    • mantle (cloak, etc.)
  • mucous (adjective)
    • mucus (noun)
  • ordinance (law)
    • ordnance (military weapons)
  • pedal (operate levers with feet; activation device)
    • peddle (sell, hawk)
  • personal (individual; private)
    • personnel (staff)
  • phosphorous (adjective)
    • phosphorus (noun)
  • principal (chief, main, leading; school administrator)
    • principle (rule)
  • prophecy (noun)
    • prophesy (verb)
  • sceptic (one who doubts)
    • septic (involving putrefaction, sepsis)
  • stationary (fixed, motionless)
    • stationery (writing materials)
  • therefor (for this purpose or thing)
    • therefore (for that reason, consequently)
  • troop (soldiers)
    • troupe (actors, performers)
  • waive (give up, forego)
    • wave (move up and down, etc.)

3.06 Words with ei and ie

The jingle "i before e except after c or when sounded as a as in neighbour and weigh" covers the rule.


  • either
  • heifer
  • neither
  • foreign
  • height
  • seize
  • forfeit
  • leisure
  • sovereign
  • weird

3.07 Verbs ending in sede, ceed and cede

Supersede is the only verb ending in sede. Exceed, proceed and succeed are the only common verbs ending in ceed. Verbs ending in cede include the following:

  • accede
  • antecede
  • cede
  • concede
  • intercede
  • precede
  • recede
  • secede

3.08 Able/ible and ative/itive endings

There is no basic rule for these endings. However, if there is a corresponding word ending in ation, the ending is usually able or ative; if the corresponding word ends in sion or tion not preceded by a, the ending is usually ible or itive:

  • affirmation
    • affirmative
  • duration
    • durable
  • information
    • informative
  • competition
    • competitive
  • division
    • divisible
  • reproduction
    • reproducible

3.09 Final consonants doubled before a suffix

Double the final consonant before y or before a suffix beginning with a vowel in a word of one syllable that ends in a single consonant preceded by a single vowel:

  • bed
    • bedded
  • dip
    • dipped
  • fat
    • fatty
  • fit
    • fitted
  • flit
    • flitting
  • gum
    • gummy
  • log
    • logged
  • mad
    • madden
  • rot
    • rotted
  • scrub
    • scrubbing
  • sit
    • sitting
  • stop
    • stopping


Do not double the final consonant in a word of one syllable if the vowel sound is long:

  • boat
    • boating
  • light
    • lighten
  • stoop
    • stooped
  • read
    • reading

Note that the preferred plural spelling of the noun bus is buses.

The final consonant is doubled in words of more than one syllable ending in a single consonant preceded by a single vowel, if the accent is on the last syllable and the suffix begins with a vowel:

  • acquit
    • acquittal
  • commit
    • committal
  • occur
    • occurrence
  • rebel
    • rebellion
  • regret
    • regretted
  • transmit
    • transmitted

Note that there is no doubling of the consonant in targeted and benefited.

3.10 Words ending in n

When the suffix ness is added to a word ending in n, a double n is formed:

  • even
    • evenness
  • green
    • greenness
  • keen
    • keenness
  • sudden
    • suddenness

3.11 Combinations with all

The final l is usually dropped when all is used as a prefix:

  • all together
    • altogether
  • all ready
    • already


  • all right

(see 3.05 Homonyms and similar-sounding words for differences in meaning)

3.12 Words ending in a silent e

The final e is usually dropped before a suffix beginning with a vowel:

  • debate
    • debatable
  • desire
    • desirable
  • dine
    • dining
  • excite
    • excitable
  • like
    • likable
  • love
    • lovable
  • make
    • makable
  • move
    • movable
  • rate
    • ratable
  • sale
    • salable
  • size
    • sizable
  • subdue
    • subduing


  • age
    • ageing
  • mile
    • mileage

However, when e follows c or g it is retained before the vowels a and o to preserve the soft sound of these consonants:

  • change, changeable but changing
  • courage, courageous
  • gauge, gaugeable but gauging
  • knowledge, knowledgeable
  • notice, noticeable but noticing
  • peace, peaceable
  • trace, traceable but tracing

Note that the e is retained even before i in some cases in order to distinguish a word from a similarly spelled one or to preserve a particular pronunciation:

  • dyeing
  • singeing
  • shoeing
  • toeing


  • routing

Words ending in a silent e generally retain the e before a suffix beginning with a consonant:

  • complete
    • completeness
  • hope
    • hopeless
  • waste
    • wasteful
  • whole
    • wholesome


  • due
    • duly
  • subtle
    • subtly
  • true
    • truly
  • whole
    • wholly

Abridgment, acknowledgment and judgment can be spelled with or without the e, but the preferred spelling is as given.

3.13 Words ending in c

In words ending in a c that has the sound of k, add k before e, i or y:

  • picnic
    • picnicking
  • panic
    • panicky
  • Quebec
    • Quebecker
  • traffic
    • trafficking

3.14 Verbs ending in ie

In verbs ending in ie, change ie to y before ing:

  • die
    • dying
  • lie
    • lying
  • tie
    • tying
  • vie
    • vying

3.15 Words ending in y

In words ending in y preceded by a consonant, change the y to i before a suffix, unless the suffix itself begins with i:

  • heavy
  • heaviest
  • lively
  • livelihood
  • salary
  • salaried
  • necessary
  • necessarily


  • copyist
  • flying
  • denying
  • trying

Note the distinction between dryer (something or someone that dries) and drier (the comparative of dry).

Words ending in y preceded by a vowel generally retain the y before a suffix:

  • annoy
    • annoyance
    • annoying
  • pay
    • payable
    • paying

3.16 Words ending in ise and ize

The following are the only common words ending in ise:

  • advertise
  • advise
  • apprise
  • arise
  • chastise
  • circumcise
  • comprise
  • compromise
  • demise
  • despise
  • devise
  • disguise
  • enterprise
  • excise
  • exercise
  • franchise
  • guise
  • improvise
  • incise
  • merchandise
  • mortise
  • premise
  • reprise
  • revise
  • supervise
  • surmise
  • surprise
  • televise

To this list should be added all words with wise as a suffix.

Note that the suffix ise cannot be replaced with ize in this group.

Use the suffix ize for most other words, including civilize, criticize, italicize, itemize, memorize and organize.

3.17 Plural forms of nouns

Note the following singular and plural forms:

  • addendum
    • addenda
  • alumna
    • alumnae
  • alumnus
    • alumni
  • analysis
    • analyses
  • antenna
    • antennae (feelers) or antennas (aerials)
  • appendix
    • appendixes (or appendices)
  • bacterium
    • bacteria
  • basis
    • bases
  • bureau
    • bureaus
  • bus
    • buses
  • census
    • censuses
  • crisis
    • crises
  • criterion
    • criteria
  • ellipsis
    • ellipses
  • erratum
    • errata
  • focus
    • focuses (not focusses, which is the preferred verb form)
  • formula
    • formulas (or formulae)
  • gas
    • gases (not gasses, which is the verb form)
  • hypothesis
    • hypotheses
  • index
    • indexes (of a book) or indices (in mathematics, statistics)
  • matrix
    • matrices
  • medium
    • (medium or media) (check dictionary for plural form to use in a given context)
  • memorandum
    • memorandums (or memoranda)
  • nucleus
    • nuclei
  • parenthesis
    • parentheses
  • phenomenon
    • phenomena
  • plateau
    • plateaus
  • surplus
    • surpluses
  • symposium
    • symposiums (or symposia)

Many other English words form their plurals irregularly, including some of those ending in y, o, f and fe.