英語スペリングルール完全ガイド

IE / EI

"i before e"

Write "ie" after most consonants (not c)

""believe", "achieve", "field", "piece""

IE / EI

"e before i after c"

Write "ei" after the letter c

""receive", "ceiling", "deceive", "perceive""

IE / EI

"ei for /eɪ/ sound"

Write "ei" when the sound is "ay"

""eight", "weight", "vein", "neighbor""

IE / EI

"weird exceptions"

A few common words break the ie/ei rule

""weird", "seize", "either", "leisure""

IE / EI

"science words"

"ei" appears in many scientific terms

""protein", "caffeine", "Einstein""

IE / EI

"grief / brief"

"ie" gives the /iː/ sound after g, r, b

""grief", "brief", "chief", "thief""

IE / EI

"neither / neither"

"ei" is used in "neither" and "either"

""Neither option is correct." (common exception)"

IE / EI

"financier"

French loanwords sometimes use "ier" without breaking the rule

""financier", "glacier", "cavalier""

サイレントE

"magic e makes vowel long"

A final "e" makes the preceding vowel say its name

""hop" → "hope"; "kit" → "kite"; "cap" → "cape""

サイレントE

"drop e before vowel suffix"

Remove silent e before -ing, -ed, -er, -able

""make" → "making"; "love" → "lovable""

サイレントE

"keep e before consonant suffix"

Keep silent e before -ment, -ness, -less, -ful

""hope" → "hopeful"; "care" → "careless""

サイレントE

"keep e after soft c or g"

Keep e in -ce/-ge before -able/-ous to preserve soft sound

""notice" → "noticeable"; "change" → "changeable""

サイレントE

"dye → dyeing"

Keep e in "dye", "hoe", "toe" before -ing to avoid confusion

""dye" → "dyeing" (not "dying")"

サイレントE

"e after v"

English words almost never end in v; add e

""have", "give", "live", "love", "dove""

サイレントE

"e after u"

"ue" at the end signals the /juː/ or /uː/ sound

""blue", "true", "argue", "continue""

サイレントE

"judge / bridge"

Write "dge" not "dj" after a short vowel

""judge", "bridge", "badge", "hedge""

子音の二重

"1-1-1 doubling rule"

Double the final consonant: 1 syllable, 1 vowel, 1 consonant

""run" → "running"; "sit" → "sitting"; "big" → "bigger""

子音の二重

"stressed final syllable"

Double when the final syllable is stressed before a vowel suffix

""begin" → "beginning"; "prefer" → "preferred""

子音の二重

"no doubling for two vowels"

Do not double after two vowels

""read" → "reading" (not "readding")"

子音の二重

"no doubling for two consonants"

Do not double when consonant cluster already exists

""help" → "helping" (not "helpping")"

子音の二重

"no doubling x or w"

"x" and "w" are never doubled before a suffix

""box" → "boxing"; "flow" → "flowing""

子音の二重

"British -l doubling"

British English doubles final -l even in unstressed syllables

"UK: "travel" → "travelling"; US: "traveling""

子音の二重

"stop → stopped"

CVC words ending in -p, -t, -n, -m follow the 1-1-1 rule

""stop" → "stopped"; "plan" → "planned""

子音の二重

"panic → panicked"

Add -k before -ed/-ing when word ends in -c

""panic" → "panicked"; "mimic" → "mimicking""

複数形

"add -s"

Most nouns simply add -s

""cat" → "cats"; "book" → "books"; "day" → "days""

複数形

"add -es after sibilants"

Add -es after -s, -sh, -ch, -x, -z

""bus" → "buses"; "box" → "boxes"; "watch" → "watches""

複数形

"consonant + y → ies"

Change y to i and add -es when a consonant precedes y

""city" → "cities"; "baby" → "babies"; "fly" → "flies""

複数形

"vowel + y → ys"

Just add -s when a vowel precedes y

""day" → "days"; "boy" → "boys"; "key" → "keys""

複数形

"f / fe → ves"

Many nouns ending in -f or -fe change to -ves

""leaf" → "leaves"; "knife" → "knives"; "wolf" → "wolves""

複数形

"o endings vary"

Some -o words add -es, others just -s

""tomato" → "tomatoes"; "photo" → "photos"; "piano" → "pianos""

複数形

"irregular plurals"

A set of common nouns have irregular plural forms

""man" → "men"; "tooth" → "teeth"; "mouse" → "mice""

複数形

"unchanged plurals"

Some nouns are the same in singular and plural

""sheep", "deer", "fish", "species", "aircraft""

Yのルール

"y → i before suffix"

Change y to i before most suffixes (except -ing)

""happy" → "happily", "happiness"; "carry" → "carried""

Yのルール

"keep y before -ing"

Always keep y before -ing to avoid double i

""try" → "trying"; "fly" → "flying"; "carry" → "carrying""

Yのルール

"y stays after vowel"

Do not change y when a vowel comes before it

""enjoy" → "enjoyed"; "play" → "played", "plays""

Yのルール

"-ify verbs"

Verbs ending in -ify follow y → i before -es, -ed, -er

""identify" → "identifies"; "clarify" → "clarified""

Yのルール

"final y adjective comparatives"

Change y to i for -er and -est comparatives

""easy" → "easier", "easiest"; "funny" → "funnier""

Yのルール

"y at word start"

Initial y is a consonant and never changes

""yellow", "yes", "year", "yet" — y stays as is"

Yのルール

"words ending -ey keep e"

Nouns ending -ey simply add -s for plural

""monkey" → "monkeys"; "turkey" → "turkeys"; "valley" → "valleys""

Yのルール

"dry → drily / dryly"

A few -y adjectives allow both y→i and y-kept adverbs

""dry" → "drily" or "dryly"; "shy" → "shily" or "shyly""

米英のスペリング差

"-or vs -our"

American English drops the u in -our words

"US: "color", "honor", "flavor"; UK: "colour", "honour", "flavour""

米英のスペリング差

"-ize vs -ise"

American English prefers -ize; British accepts both but -ise is common

"US: "organize", "realize"; UK: "organise", "realise""

米英のスペリング差

"-er vs -re"

American reverses -re endings to -er

"US: "center", "theater", "fiber"; UK: "centre", "theatre", "fibre""

米英のスペリング差

"-ense vs -ence"

Several nouns differ between -ense (US) and -ence (UK)

"US: "defense", "offense"; UK: "defence", "offence""

米英のスペリング差

"-og vs -ogue"

American English shortens -ogue to -og

"US: "catalog", "dialog"; UK: "catalogue", "dialogue""

米英のスペリング差

"double l in British"

British doubles -l in verbs before vowel suffixes; American does not

"UK: "travelled", "labelled"; US: "traveled", "labeled""

米英のスペリング差

"-yze vs -yse"

American uses -yze; British uses -yse

"US: "analyze", "paralyze"; UK: "analyse", "paralyse""

米英のスペリング差

"-ment spellings"

A handful of common nouns differ in -ment endings

"US: "judgment"; UK: "judgement" (both acceptable in US too)"