English Spelling Rules

If you had asked me a decade ago about English spelling rules, I probably would have cried and told you that the English spelling system made no sense. But then I discovered Structured Word Inquiry (SWI) thanks to Gina Cooke at Linguist-Educator Exchange (LEX) and Shameless Spelling. Over the past few years, I have been studying and learning about the rules of the English spelling system. And English spelling is a system with rules. The following sections explain and exemplify the English spelling rules needed for the written language.

Lexical and Functional Spellings

Words exist on a lexical-functional continuum. Lexical, or content, words express discernible lexical meanings. Lexical words are easy to define. Lexical words are easy to draw or picture. Functional, or function, words express little lexical meaning but express grammatical or structural meaning among other words. Word classes such as nouns, adjectives, most verbs, and some adverbs are lexical words. Word classes such as determiners, pronouns, conjunctions, and some auxiliary verbs are functional words. Prepositions and many adverbs are lexical-functional words, combining both lexical and functional properties.

Spellings also exist on the lexical-functional continuum. Lexical spellings have three or more letters. Functional spellings can have one or two (or more) letters. The difference is especially apparent in homophone pairs of lexical and functional words. For example:

a (functional, determiner)
am (functional, auxiliary verb)
is (functional, auxiliary verb)
he (functional, pronoun)
it (functional, pronoun)
me (functional, pronoun)
us (functional, pronoun)
my (functional, determiner)
of (functional, preposition)
as (functional, preposition)
if (functional, preposition)

Ann/Anne (lexical)
an (functional, determiner)
bee (lexical)
be (functional, auxiliary verb)
inn (lexical)
in (functional, preposition)
eye (lexical)
I (functional, pronoun)
wee (lexical)
we (functional, pronoun)
know (lexical)
no (functional, determiner/interjection)
awn (lexical)
on (functional, preposition)
ore (lexical)
oar (lexical)
or (functional, conjunction)
sew (lexical)
sow (lexical)
so (functional, conjunction/adverb/interjection)
two (lexical-functional, determiner/numeral)
too (lexical-functional, adverb)
to (functional, preposition/p-word)

The verb do is both lexical and functional and has a functional spelling. Modern do comes from Middle English do, which came from Old English don. The verb go is also both lexical and functional (“be going to”) and has a functional spelling. Modern go comes from Old English gan. The grapheme <o> is the only grapheme that works across each family to spell the vowel: do ~ does ~ doing ~ done and go ~ goes ~ going ~ gone.

The lexical word ox comes from Middle English oxe and the lexical word ax comes from Modern English axe. The grapheme <x> never doubles.

The letter-length rule applies to complete, native English words. For example, the lexical aa meaning “a lava flow of basaltic rock associated with Hawaiian volcanoes” is a loanword borrowed directly from the Hawaiian a’a. The lexical ad is a clip (shortening) of advertisement. Though lexical, neither aa nor ad are complete, native words.

Final Letters

A complete, native, lexical English word cannot end in , <o>, , or <v>. A replaceable <e> prevents a word from ending in , <o>, , or <v>. For example:

die
lie
pie
tie
doe
foe
hoe
woe
blue
cue
due
glue
hue
true
queue
bisque
give
have
love
move

Words that end in , <o>, , or <v> are not complete, not native, and/or not lexical. For example:

taxi (clip of taxicab, blend of taximeter cab)
hi (functional, interjection)
ski (Norwegian loanword)
ziti (Italian loanword)
bikini (French loanword)
auto (clip of automobile or automatic)
bro (clip of brother)
memo (clip of memorandum)
zoo (clip of zoological gardens)
judo (Japanese loanword)
tofu (Japanese loanword)
taco (Mexican Spanish loanword)
no (functional, determiner/interjection)
so (functional, conjunction/adverb/interjection)
ago (functional, postposition)
flu (clip of influenza)
muumuu (Hawaiian loanword)
gnu (Khoisan loanword via Dutch)
you (functional, pronoun)
rev (clip of revolution)
dev (clip of development or developer)
improv (clip of improvisation)
shiv (modern slang coinage)

Consonant Doubling

Suffixes that begin with a vowel and the -le suffix cause doubling when affixed to a base that ends in one vowel and one consonant other than <w>, <x>, or <y>. For example:

Plot + ed -> plotted
Jog + ing -> jogging
Big + er -> bigger
Hot + est -> hottest
Run + y -> runny
Sad + en -> sadden
Hug + able -> huggable
Bag + age -> baggage
Red + ish -> reddish
Snug + le -> snuggle

The graphemes <w>, <x>, and <y> never double. In the morpheme-final position, the letter <w> is always part of a vowel diagraph as in <aw>, <ew>, and <ow>. The grapheme <y> is a consonant grapheme only in a morpheme-initial position as in yes and you. At the end of a morpheme, the letter <y> is a vowel grapheme or part of a vowel digraph as in <ay>, <ey>, and <oy>. (See also <y> Toggles with .) For example:

Wow + ed -> wowed (<w.ow>)
Paw + ing -> pawing (<p.aw>)
Low + er -> lower (<l.ow>)
Few + est -> fewest (<f.ew>)
Row + er -> rower (<r.ow>)
Snow + y -> snowy (<s.n.ow>)
New + ish -> newish (<n.ew>)
Sex + ist -> sexist
Sex + ism -> sexism
Toy + ed -> toyed (<t.oy>)
Spy + ing -> spying

Suffixes do not cause doubling of graphemes in other suffixes. For example:

Red + en + ed -> reddened
Zip + er + ing -> zippering
Bright + en + er -> brightener
Slip + er + y -> slippery

Replaceable <e>

Suffixes that begin with a vowel and the -le suffix replace a replaceable <e> in both bases and other suffixes. For example:

Hope + ing -> hoping
Cute + ish -> cutish
Fuse + ion -> fusion
Prime + ate -> primate
Serve + ant -> observant
Solve + ent -> solvent
Lade + le -> ladle

A suffix that begins with a vowel other than <e> does not replace a replaceable <e> that marks the phonology of a <c> or <g>. For example:

re + Place + able -> replaceable
Trace + able -> traceable
Change + able -> changeable
Age + ist -> ageist

Twinge + ed -> twinged
in + Noce + ence -> innocence
com + Place + ent -> complacent
Urge + ent -> urgent

-s and -es Allomorphs

The noun plural and third person singular suffixes -s and -es are allomorphs. Allomorphs are morphemes that vary in sound and spelling but not meaning. Both -s and -es form the plural of regular nouns and the third person singular simple present of verbs. An -es begins with a vowel and can cause doubling. (See Consonant Doubling.) The -es suffix adds an extra syllable after a sibilant. For example:

Glass + es -> glasses
Wash + es -> washes
Match + es -> matches
Wax + es -> waxes
Buzz + es -> buzzes

The -es suffix forms the third person singular simple present of the verbs go and do:

Go + es -> goes
Do + es -> does

The -es suffix forms the plural and third person singular of nouns and verbs that end in the grapheme <y>. (See also <y> Toggles with .) For example:

Candy + es -> candies
Empty + es -> empties
Butter + Fly + es -> butterflies
Car + y + es -> carries
ap + Ply + es -> applies
Magn + i + Fy + es -> magnifies

The -es suffix also forms the plural of some nouns (and the third person singular simple present of some verbs) that end in the grapheme <o>:

Potato + es -> potatoes
Tomato + es -> tomatoes
Hero + es -> heroes
Veto + es -> vetoes (noun and verb)
Echo + es -> echoes (noun and verb)

Note that some nouns and verbs that end in <o> take both -s and -es in the plural and third person singular. For example:

avocado ~ avocados ~ avocadoes
buffalo ~ buffalos ~ buffaloes
mosquito ~ mosquitos ~ mosquitoes
tornado ~ tornados ~ tornadoes
zero ~ zeros ~ zeroes

The majority of nouns and verbs that end in <o> take the -s suffix. For example:

Cello + s -> cellos
Piano + s -> pianos
Taco + s -> tacos

If in doubt about a noun or verb that ends in <o>, consult a dictionary.

Final <f> and <fe>

For some nouns spelled with a final <f> or <fe> in the singular, the base of the plural is spelled with a final <ve> and then the -s suffix affixes to the plural base. The change applies to some native English words. Understanding these plural forms requires knowledge of Old English allophones. Similar to allomorphs, allophones are variations of speech sounds that represent a single phoneme but do not change meaning. In Old English, the fricative /f/ had the voiced allophone [v] between vowels or voiced consonants. By Middle English, [f] and [v] developed into separate sounds. The sound change between the singular and plural of some nouns continued from Old English into Modern English; the spelling changed to reflect the pronunciation. The same change applies to some verbs spelled with a final <f> or <fe> in the third person singular present tense. For example:

knife ~ knives
leaf ~ leaves
thief ~ thieves
wife ~ wives
wolf ~ wolves

<y> Toggles with

Suffixes that begin with a letter other than cause a word-final grapheme <y> to toggle with . Toggling applies to the grapheme <y> in both bases and suffixes. For example:

Hap + y + ness -> happiness
Ugly + ness -> ugliness
Live + ly + hood -> livelihood
Lone + ly + ness -> loneliness
Busy + est -> busiest
Health + y + er -> healthier

A suffix that begins with does not cause toggling of the grapheme <y>. For example:

Fly + ing -> flying
Try + ing -> trying
Babe + y + ish -> babyish
Gallery + ite -> galleryite

Toggling does not occur when the need to distinguish between homophones arises such as in business “occupation, job, trade” versus busyness “the state of being busy.”

Toggling also never occurs in a digraph that contains the letter <y> such as <ay>, <ey>, and <oy> or when a vowel proceeds a <y>. For example:

Monkey + ing -> monkeying
Cockney + ish -> Cockneyish
Stay + ed -> stayed
Play + ing -> playing
de + Stroy + er -> destroyer
Buy + er -> buyer
Guy + ish -> guyish

<c> Toggles with <ck>

Suffixes that begin with <e>, , or <y> cause a word-final grapheme <c> to toggle with <ck> to preserve the phonology of the <c>. For example:

Picnic + ing -> picnicking
Mimic + ed -> mimicked
Traffic + er -> trafficker

Connecting Vowels

A connecting vowel is a vowel that connects morphemes. The connecting vowels in English are -e-, -i-, -o-, and -u-. The connecting vowels come from Latin (-e-, -i-, -u-) and Greek (-o-). A connecting vowel must follow a base or suffix. Connecting vowels can replace the replaceable <e>. (See Replaceable <e>.) For example:

Ge + o + Graph + y -> geology
Bi + o + Sphere -> biosphere
Ace + id + i + Fy -> acidify
Art + i + Fice -> artifice
Muse + e + um -> museum
Rose + e + ate -> roseate
Vace + u + um -> vacuum
Act + u + al -> actual

A connecting vowel always connects two morphemes. Some clips appear to end in a connecting vowel but are actually shortened words created from other words. For example:

Phote + o + Graph -> photograph ~ photo
Bi + o + Log(e) + y -> biology ~ bio
Type + o + Graph + ic + al -> typographical (error) ~ typo

Potential Vowel

Some suffixes and bases have a potential vowel (<e> or <o>). Every phonemic syllable must be written with at least one vowel letter, so a potential <e> or <o> surfaces when needed, specifically to spell the unstressed [ə] and to be the vowel letter in a syllable. For example:

Act + (o)r -> actor
Hunt + (e)r -> hunter
Ancest(o)r -> ancestor
Met(e)r -> meter
Wint(e)r -> winter
Dece + em + b(e)r -> December

The potential <e> or <o> does not surface when not needed, specifically when a suffix contains a vowel grapheme that becomes of the written vowel of the syllable. For example:

Act + (o)r + ess -> actress
Hunt + (e)r + ess -> huntress
Ancest(o)r + al -> ancestral
Met(e)r + ic -> metric
Wint(e)r + y -> wintry
Dece + em + b(e)r + ist -> Decembrist

Some bases also have a potential <e> that surfaces to prevent doubling when affixing a suffix but that does not surface when compounding with another base, when word-final, or when affixed with a suffix that starts with a consonant. For example:

Nav(e) + al -> naval
Ast(e)r + al -> astral
Bureau + Crat(e) + ic -> bureaucratic
Octa + Gon(e) + al -> octagonal
Oxy + Gen(e) + ate -> oxygenate
Judg(e) -> judge
Frag(e) + ile -> fragile

Nav(e) + Ige + ate -> navigate
Ast(e)r + Onym -> astronym
Bureau + Crat(e) -> bureaucrat
Octa + Gon(e) -> octagon
Oxy + Gen(e) -> oxygen
Judg(e) + ment -> judgment
Frag(e) + ment -> fragment

Terminal Position Base Simplification

Some bases with a morpheme-final double consonant have a simplified base in the terminal position of a word or when affixed with a suffix that begins with a consonant. For example:

Ter(r) + or -> terror
Ter(r) + i + Fy -> terrify
Ter(r) + i + Fic(e) -> terrific
Ter(r) + ible -> terrible
de + Ter(r) + ent -> deterrent
de + Ter(r) -> deter
de + Ter(r) + s -> deters

Hor(r) + or -> horror
Hor(r) + ible -> horrible
Hor(r) + i + Fy -> horrify
ab + Hor(r) -> abhor
ab + Hor(r) + s -> abhors
ab + Hor(r) + ment -> abhorment

War(r) + ing -> warring
War(r) + i + or -> warrior
War(r) -> war
War(r) + s -> wars

Compounding and Prefixing

Compounding a base and base does not cause any other spelling changes. (See Potential Vowel.) For example:

Base + Ball -> baseball
Grape + Fruit -> grapefruit
Dry + Wall -> drywall
Any + One -> anyone
Crab + Apple -> crabapple
My + Self -> myself

Affixing a prefix to a base or another prefix does not cause any spelling changes. For example:

re + Read -> reread
un + en + Cumber -> unencumber
pre + sup + Pose -> presuppose
dis + in + Cline -> disincline
un + in + Stall -> uninstall
anti + de + Press + ant -> antidepressant

Alternative Spellings

Some words have multiple spellings. For example:

gray ~ grey
theater ~ theatre
color ~ colour
wintry ~ wintery
judgment ~ judgement
doughnut ~ donut
mosquitoes ~ mosquitos
likable ~ likeable
linchpin ~ lynchpin
okay ~ OK
pajamas ~ pyjamas
advisor ~ adviser
savory ~ savoury
authorize ~ authorize
catalog ~ catalogue
check ~ cheque
program ~ programme
canceled ~ cancelled
archeology ~ archaeology
jewelry ~ jewellery
disk ~ disc
reenroll ~ re-enroll

Many times the spelling differences depend on the English variety such as American English versus British English. Others are stylistic choices. If in doubt, consult a dictionary.

References

Etymonline: https://www.etymonline.com/
LEX™ Grapheme Deck – 3rd Edition: https://linguisteducatorexchange.com/product/lex-grapheme-deck-3rd-edition/
List of Spelling Variants: https://en.wikipedia.org/wiki/Wikipedia:List_of_spelling_variants
Teach a Student to Read: SWI: https://teachastudenttoread.com/swi/