-
- -able and -ible
- -esque
A
- A cappella
- A la
- A leg up
- A lot vs. alot
- A whole nother
- Abandon vs. abandonment
- Abbreviations, acronyms, and initialisms
- Abecedarius
- Abide, abided, abode
- Abjure vs. adjure
- Abolishment vs. abolition
- Aborted vs. abortive
- About-face
- Abstruse vs. obtuse
- Acclimate, acclimatise, and acclimatize
- Accord vs. accordance
- Acephalous
- Achilles' heel
- Acquaintanceship
- Active voice vs. passive voice
- Actual fact
- Ad hoc
- Ad hominem (usage)
- Ad infinitum
- Ad nauseam
- Adaption vs. adaptation
- Added bonus
- Addicting vs. addictive
- Addiction vs. dependence
- Addition vs. edition
- Adjectives
- Administrate
- Admission and admittance
- Adopted vs. adoptive
- Adverb placement
- Adverbial clauses
- Adverbs
- Adverbs from -ly adjectives
- Adverse vs. averse
- Advert vs. avert
- Advice vs. advise
- Adviser vs. advisor
- Aegis
- Aeon vs. eon
- Aeroplane vs. airplane
- Aesthetic vs. ascetic
- Affect vs. effect
- Afflict vs. inflict
- African-American vs. black
- After having
- Afterward vs. afterword
- Ageing vs. aging
- Agent and recipient nouns
- Aggravate
- Aggression vs. aggressiveness
- Agnostic vs. atheist
- Ahold
- Aid vs. aide
- Ain't
- Aisle vs. isle
- Alas
- Albeit
- All but
- All in all
- All right vs. alright
- All together vs. altogether
- Alligator vs. crocodile
- Allude vs. elude
- Allusion, elusion, and illusion
- Already vs. all ready
- Altar vs. alter
- Alter ego
- Alternate vs. alternative
- Although vs. though
- Aluminium vs. aluminum
- Alumna, alumnae, alumni, and alumnus
- Amalgam vs. amalgamation
- Ambiance vs. ambience
- Amend vs. emend
- American
- Amiable vs. amicable
- Amok vs. amuck
- Among vs. amongst
- Amoral vs. immoral
- Amount vs. number
- Ample
- Amuse vs. bemuse
- An historic
- Analog vs. analogue
- Analyse vs. analyze
- Anapest
- Anathema
- And yet
- Animal adjectives
- Annex vs. annexe
- Another think coming
- Antennae vs. antennas
- Antivenom
- Anyplace
- Anyway vs. anyways
- Apologise vs. apologize
- Apostrophe
- Apostrophe
- Apotheosis
- Appositives
- Appropriate vs. expropriate
- Apropos
- Argumentative vs. argumentive
- Armor vs. armour
- Around the clock vs. round the clock
- Around vs. round
- Arouse vs. rouse
- Arrant vs. errant
- Artefact vs. artifact
- As far as
- As of late and of late
- As per
- As yet and as of yet
- Ascared
- Ascent vs. assent
- Ascent, ascendance, ascendancy, etc.
- Asphalt, cement, concrete, pavement
- Assail vs. assault
- Assent vs. consent
- Assume vs. presume
- At loggerheads
- Attain vs. obtain
- Attend to and tend to
- Au contraire
- Auger vs. augur
- Aught
- Authoritative vs. authoritive
- Autumn vs. fall
- Auxiliary verbs
- Avail
- Avant-garde
- Awhile vs. a while
- Ax vs. axe
- Axel vs. axle
B
- Back up vs. backup
- Backyard, back yard, and back-yard
- Bad rap vs. bad wrap
- Bailout, bail out, and bail-out
- Bait vs. bate
- Bald-faced vs. boldface
- Baloney vs. bologna
- Ban vs. bar
- Bankster
- Bar mitzvah and bat mitzvah
- Barbed wire
- Bard
- Bare vs. bear
- Basis (on a daily basis, on a regular basis)
- Bawl out
- Bazaar vs. bizarre
- Bear market, bull market, bearish, bullish
- Beckon call
- Beeline
- Beggars belief
- Begging the question (fallacy)
- Begging the question (usage)
- Behavior vs. behaviour
- Belated
- Belie
- Bellwether
- Bereaved and bereft
- Betwixt
- Beyond the pale
- Biceps and triceps
- Bight vs. bite
- Bit vs. bitten
- Blaspheme
- Blatant vs. flagrant
- Blatantly obvious
- Blather vs. blither
- Bloc vs. block
- Blond and blonde
- Blowout and blow out
- Blowup, blow-up, and blow up
- Boldface text
- Bona fide and bona fides
- Borne vs. born
- Boughten
- Bourgeois, bourgeoisie
- Brainchild
- Breach, breech, broach
- Breath and breadth
- Breath vs. breathe
- Bridle vs. bridal
- Briton
- Broach vs. brooch
- Browse through
- Brung, brang
- Brussels sprout
- Build up vs. buildup
- Bulk, balk, and baulk
- Bunk, bunkum, and buncombe
- Bupkis
- Burgle and burglarize
- Burned vs. burnt
- Burnout vs. burn out
- Bursted
- Burthen
- Bus stop or busstop?
- But vs. yet
- But yet
- By and by vs. by the by
- By dint of
C
- C'est la vie
- Cacao vs. cocoa
- Cache vs. cachet
- Caddie vs. caddy
- Cahoots
- Callous vs. callus
- Calvary vs. cavalry
- Canard
- Canon vs. cannon
- Canvas vs. canvass
- Capitol vs. capital
- Card shark vs. card sharp
- Carrot, carat, karat, caret
- Casted
- Catachresis
- Catalog vs. catalogue
- Catch-22
- Catty-corner, kitty-corner, and cater-cornered
- Cautiousness
- Caveat
- Cede vs. concede
- Center vs. centre
- Centrifugal vs. centripetal
- Centrifuge vs. subterfuge
- Centuries
- Certainty and certitude
- Cession vs. session
- Chasten vs. chastise
- Check up vs. checkup
- Check vs. cheque
- Chic vs. sheik
- Childish vs. childlike
- Chink vs. kink
- Chock-full
- Chopper vs. copter
- Classic vs. classical
- Clauses
- Clean vs. cleanse
- Cleanup vs. clean up
- Clench vs. clinch
- Cliché
- Client vs. customer
- Cliffs Notes
- Climactic and climatic
- Close proximity
- Close rhyme
- Closed-minded
- Co-mingle, commingle, intermingle
- Co-op vs. co-opt
- Collaborate together
- Collective nouns
- College vs. university
- Collegial vs. collegiate
- Colon
- Color vs. colour
- Colosseum and coliseum
- Combine together
- Comedienne
- Comic vs. comical
- Commas
- Commentator vs. commenter
- Common French expressions
- Comparative and superlative adverbs
- Compel vs. impel
- Complacent vs. complaisant
- Complement vs. compliment
- Complex sentences
- Complex-compound sentences
- Compound sentences
- Comprise, compose
- Concave vs. convex
- Conceive vs. perceive
- Concerted
- Condemn, condone
- Confidant, confidante
- Conjunctions
- Conjunctions to start sentences
- Connexion
- Connote, denote
- Contemporary vs. contemporaneous
- Contemptible vs. contemptuous
- Continual vs. continuous
- Contractions
- Contumely
- Conversate
- Cooperate vs. co-operate
- Coordinate adjectives
- Copyright vs. copywrite
- Coral vs. corral
- Cord vs. chord
- Cornet vs. coronet
- Corollary vs. correlation
- Cosmetology vs. cosmology
- Cosy vs. cozy
- Could care less vs. couldn't care less
- Council vs. counsel
- Counselor vs. counsellor
- Cover all the bases
- Crap
- Crayfish, crawfish, crawdad, etc.
- Cream of the crop
- Credible vs. credulous
- Creeped vs. crept
- Crevice vs. crevasse
- Crick, creek
- Crier vs. cryer
- Criteria and criterion
- Critical juncture
- Cue vs. queue
- Cum
- Curb vs. kerb
- Currently
- Cut-and-dried
- Cutesy
- Cyclist vs. biker
D
- D'oh
- Dactyl
- Dam vs. damn
- Dampen, damper, dampener
- Danglers
- Daresay
- Data
- Dates and commas
- Davy Jones's locker
- Day in age
- De facto
- De rigueur
- Dead set, dead-set, deadset
- Dealt vs. dealed
- Dearth
- Decent vs. descent
- Deceptively
- Decidedly
- Deconstruction
- Decry vs. descry
- Deduction vs. induction
- Deep-seeded vs. deep-seated
- Defence vs. defense
- Definite articles
- Definite articles
- Defuse vs. diffuse
- Deign
- Demur vs. demure
- Dependant vs. dependent
- Deprecate, depreciate, and self-deprecating
- Derring-do
- Descendant vs. descendent
- Despite vs. in spite of
- Destroy, destruct, self-destruct
- Detract vs. distract
- Device and devise
- Dialectal vs. dialectical
- Dice and die
- Dike vs. dyke
- Dilemma
- Directional words
- Dis vs. diss
- Disassemble vs. dissemble
- Disburse vs. disperse
- Disc vs. disk
- Discombobulate
- Disconnect
- Discrete vs. discreet
- Disillusion, dissolution
- Dispatch vs. despatch
- Dispense with vs. dispose of
- Dissociate vs. disassociate
- Distrust vs. mistrust
- Divers and diverse
- Divorcée, divorcé, divorcee
- Do apologize
- Do damage to
- Do harm to
- Dog days
- Dog-eat-dog and doggy-dog
- Dole out vs. doll out
- Doppelgänger
- Double and redouble
- Doubtlessly
- Doughnut vs. donut
- Douse vs. dowse
- Dove vs. dived
- Down the pike vs. down the pipe
- Downfall vs. downside
- Draft vs. draught
- Dragged vs. drug
- Dreamed vs. dreamt
- Dribs and drabs
- Drier vs. dryer
- Droll
- Du jour
- Dual vs. duel
- Duck tape (duct tape)
- During the course of
- Dwarfs vs. dwarves
- Dyeing vs. dying
E
- E-book, ebook, eBook
- E-mail vs. email
- E. coli
- Each and every
- Each other, one another
- Early beginnings
- Earth (capitalization)
- Earthy vs. earthly
- Economic vs. economical
- Economics vs. finance
- Eek vs. eke
- Elder, eldest
- Elegy vs. eulogy
- Elicit vs. illicit
- Ellipsis
- Elocution vs. locution
- Em-dash
- Emigrate vs. immigrate
- Empathetic vs. empathic
- Empathy vs. sympathy
- En route
- En-dash
- Enclose vs. inclose
- End result
- Endear
- Endeavor, endeavour
- Endemic vs. epidemic
- Enervate and innervate
- England, Great Britain, United Kingdom
- English moods (imperative, indicative, and subjunctive)
- Engrain vs. ingrain
- Enormity
- Enquire vs. inquire
- Ensure, insure, assure
- Enthuse
- Entomology vs. etymology
- Envelop vs. envelope
- Envision vs. envisage
- Envision vs. invision
- Envoi vs. envoy
- Epicenter
- Epigram vs. epigraph
- Eponymous
- Equable, equatable, equitable
- Equally as
- Equivalence vs. equivalency
- Ere vs. err
- Ergo
- Ersatz
- Especial
- Espy
- Estimate vs. estimation
- Et al.
- Et cetera (etc.)
- Ethics and morals
- Ethnicity vs. race
- Evacuate
- Everyday vs. every day
- Everything happens for a reason
- Evoke vs. invoke
- Ex post facto
- Exalt vs. exult
- Exclamation point
- Exercise vs. exorcise
- Exhibit vs. exhibition
- Existential
- Expectant vs. expecting
- Exploitative vs. exploitive
- Expresso
F
- Factoid
- Fair vs. fare
- Fait accompli
- False pretenses
- Falsehood, falsity, and falseness
- Far be it for me
- Far distance
- Far East, Middle East, Near East
- Farther vs. further
- Fastly
- Faux
- Faux pas
- Favor vs. favour
- Favorite vs. favourite
- Faze vs. phase
- Fearful vs. fearsome
- Fellow classmates
- Feminity vs. femininity
- Ferret out
- Fervid vs. fervent
- Few in number
- Fey and fay
- Fiancé and fiancée
- Fiber vs. fibre
- Fiction vs. nonfiction
- Fictional vs. fictitious
- Figurehead
- Filet vs. fillet
- Final destination
- Final outcome
- Final result
- Financer vs. financier
- Fine-tooth comb or fine-toothed comb?
- Firefight
- Firing line vs. line of fire
- First and foremost
- First discovered
- First-world and third-world
- Firstly, secondly, thirdly, etc.
- Fish vs. fishes
- Fit vs. fitted
- Flack vs. flak
- Flair vs. flare
- Flammable vs. inflammable
- Flaunt vs. flout
- Flavor vs. flavour
- Flesh out vs. flush out
- Fleshly vs. fleshy
- Flied
- Flier vs. flyer
- Flora and fauna
- Flotsam and jetsam
- Flounder vs. founder
- Follow up, follow-up, followup
- Foolproof vs. full-proof
- Foot
- Football fields
- For all intensive purposes
- For god's sake
- For goodness' sake
- For heaven's sake
- For the duration of
- For the purpose of
- Forbear vs. forebear
- Forbidding vs. foreboding
- Force majeure
- Forcefulness
- Forego vs. forgo
- Foreword vs. forward
- Former and latter
- Fortuitous vs. fortunate
- Forty vs. fourty
- Forward vs. forwards
- Frankenstein, Frankenstein's monster
- Fraught
- Free gift
- Free rein vs. free reign
- French accent marks
- French alphabet pronunciation
- French days and months
- French greetings and salutations
- French indefinite articles
- French noun gender
- French numbers
- French partitive article
- Freshwater
- Fritter away
- Frivolity vs. frivolousness
- Full stop vs. period
- Full-fledged and fully fledged
- Fulsome
- Fundament
- Funereal
- Furor vs. furore
- Future plans
- FWIW
G
- Gaff vs. gaffe
- Galore
- Gambit
- Gantlet vs. gauntlet
- Gaol vs. jail
- Gases vs. gasses
- Gaudy vs. gawdy
- Gay
- Gender and sex
- General consensus
- Gerunds
- Get down to brass tacks
- Get religion
- Gibe, jibe, jive, gybe
- Gift (as a verb)
- Gild vs. guild
- Gimme
- Ginormous
- Glad-hand
- Glamour vs. glamor
- Glom onto
- Gobbledygook
- Gobsmacked
- God (capitalization)
- Godspeed
- Goes without saying
- Gonna
- Goodly
- Gorilla vs. guerrilla
- Governance vs. government
- Grammar vs. usage
- Gray vs. grey
- Grill vs. grille
- Grinded
- Grisly vs. grizzly
- Guesstimate
- Gymnasia vs. gymnasiums
H
- Habeas corpus
- Hail vs. hale
- Hair's breadth
- Half-mast and half-staff
- Halve
- Handful and handfuls
- Handicap vs. handicapped
- Hands down
- Hangar vs. hanger
- Hanged vs. hung
- Happenstance
- Hara-kiri
- Harbor vs. harbour
- Hardy vs. hearty
- Hare vs. rabbit
- Harebrained
- Hark, harken, and hearken
- Healthcare
- Healthful vs. healthy
- Hear, hear
- Heighth
- Hence
- Heroin vs. heroine
- Heterogeneous vs. heterogenous
- Heterometric
- Hew vs. hue
- Hie
- Highfalutin
- Hippopotami, hippopotamuses, hippos
- Historic milestone
- Historic vs. historical
- Histrionic and histrionics
- Hoard vs. horde
- Home in vs. hone in
- Homely vs. homey
- Homo sapiens
- Homogenous vs. homogeneous
- Hoover vs. vacuum
- Hosanna
- Humongous
- Humor vs. humour
- Humorousness
- Humus vs. hummus
- Hunter-gatherer
- Hurdle vs. hurtle
- Hurrah, hooray, hurray
- Hyphen
I
- Ice tea or iced tea?
- Idea vs. ideal
- Ideogram
- Idle, idol, idyll
- If you will
- Ilk
- Illegible vs. unreadable
- Imagism
- Immanent, imminent, and eminent
- Immunity vs. impunity
- IMO
- Impactful
- Impassable vs. impassible
- Impassive vs. passive
- Impending vs. pending
- Imperious vs. impervious
- Impinge vs. infringe
- Imply vs. infer
- Impugn vs. impute
- In excess of
- In terms of
- In the affirmative
- In the course of
- In the midst of
- In the offing
- In the process of
- In the throes of
- In vogue, en vogue
- Inalienable vs. unalienable
- Incipient, insipient, and insipid
- Inclimate
- Incomparable vs. uncomparable
- Incredible vs. incredulous
- Incubus, succubus
- Indefinite articles
- Indexes vs. indices
- Inequality vs. inequity
- Infect vs. infest
- Ingenious vs. ingenuous
- Insofar
- Instantly vs. instantaneously
- Instinctive vs. instinctual
- Intact
- Inter-, intra-
- Interact with each other
- Interjections
- Interment vs. internment
- Internet (capitalization)
- Interpretative vs. interpretive
- Invaluable vs. valuable
- Ironic
- Ironical
- Irregular plural nouns
- Isometric
- Italics (when to italicize)
- Iteration
- Its vs. it's
J
- Jam vs. jamb
- Jeremiad
- Jewelry vs. jewellery
- Join together
- Joint cooperation
- Junction vs. juncture
- Junkie vs. junky
- Jury-rig, jerry-rig, jerry-built
- Just deserts or just desserts?
- Just exactly
K
- Ketchup, catsup, catchup
- Kibosh
- Kick off, kickoff, kick-off
- Kick the can down the road
- Knee-jerk, kneejerk
- Knit vs. knitted
- Kowtow
L
- Labor vs. labour
- Laissez-faire
- Landlubber
- Lasagna vs. lasagne
- Laudable vs. laudatory
- Lay and lie
- Lead vs. lede
- Leaped vs. leapt
- Learned vs. learnt
- Led vs. lead
- Leftover vs. left over
- Lend vs. loan
- Lended
- Less vs. fewer
- Lest
- Levee vs. levy
- Libel vs. slander
- Licence vs. license
- Licorice vs. liquorice
- Lighted vs. lit
- Lightening vs. lightning
- Like gangbusters
- Linchpin vs. lynchpin
- Lite
- Liter vs. litre
- Literally vs. figuratively
- Lo, lo and behold
- Loath, loathe, loth
- Log on vs. log in
- Lonely vs. lonesome
- Longetivity vs. longevity
- Loose vs. lose
- Lorry
- Lowlife
- Luddite
- Luxuriant vs. luxurious
M
- Magnate vs. magnet
- Make do vs. make due
- Maleficent vs. malevolent
- Mancession
- Maneuver vs. manoeuvre
- Mantel vs. mantle
- Manually by hand
- Marinade vs. marinate
- Marshal vs. martial
- Masterful, masterly
- Materiel vs. material
- Math vs. maths
- Maul vs. mull
- Mayonnaise vs. mayonaise
- Meager vs. meagre
- Means
- Medal, metal, mettle
- Media vs. mediums
- Mediator vs. moderator
- Melted vs. molten
- Mental attitude
- Merge together
- Meta
- Metaphoric vs. metaphorical
- Meteoroid, meteor, meteorite, and meteoric rise
- Meter vs. metre
- Methinks
- Mic vs. mike
- Mice vs. mouses
- Midriff
- Minuscule, miniscule
- Minutia, minutiae
- Mirandize
- Mischievous or mischievious?
- Modern
- Modus operandi (m.o, MO)
- Mold vs. mould
- Mollycoddle
- Moment in time
- Momentarily
- Money-grabbing vs. money-grubbing
- Monkey vs. ape
- Moot vs. mute
- Morays vs. mores
- Mothball
- Mother lode
- Mowed vs. mown
- Muchly
- Mucous vs. mucus
- Murderers' row
- Must of
- Mustache, moustache, and mustachio
- Muumuu
- Myriad
N
- Namesake
- Nary a
- Naught and nought
- Nauseous, nauseated, and nauseating
- Naval vs. navel
- Neandertal vs. neanderthal
- Neck and neck
- Negative prefixes
- Neighbor vs. neighbour
- Newfangled
- No one vs. noone
- Non sequitur
- Non-finite verbs
- Non-profit, nonprofit, and not-for-profit
- Nonplussed
- Normalcy vs. normality
- Northernly, southernly, westernly, easternly
- Not hardly
- Not in a position to
- Not un-
- Notwithstanding
- Nouns
- Nouns as adjectives
- Numerals
O
- O vs. oh
- Object lesson
- Objects
- Observance vs. observation
- Obsolescent vs. obsolete
- Ocher vs. ochre
- Octopi vs. octopuses
- Odor vs. odour
- Off of
- Off the cuff
- Offence vs. offense
- Offhand
- Oftentimes
- Oh well
- OK vs. okay
- Old adage
- Olive branch
- Omelet vs. omelette
- On steroids
- On the fritz
- On the lam
- On the up and up
- On the wagon and off the wagon
- Onboard vs. on board
- One fell swoop
- One in the same
- One-time vs. onetime
- Oneself vs. one's self
- Online or on-line?
- Onus
- Opossum vs. possum
- Oppress, repress, suppress
- Oral vs. verbal
- Ordinance vs. ordnance
- Organise vs. organize
- Orientate
- Ouster
- Out and out
- Outside of
- Outward appearances
- Over- and under-
- Overexaggerate
- Overly
- Overnight vs. over night
- Overtones vs. undertones
- Oxymorons
P
- Paddy wagon
- Paean, paeon, peon
- Pajamas vs. pyjamas
- Palate, palette, pallet
- Palindrome (poetry)
- Par excellence
- Paralyse vs. paralyze
- Paramount vs. tantamount
- Parentheses
- Parricide vs. patricide
- Part and parcel
- Participial prepositions
- Participles
- Pass the buck and the buck stops
- Passed vs. past
- Past experience
- Past history
- Patsy
- Payback vs. pay back
- Peace of mind vs. piece of [one's] mind
- Peaceable vs. peaceful
- Peak, peek, pique
- Peal vs. peel
- Pedal, peddle, and petal
- Pell-mell
- Penal vs. penile
- Pendant vs. pendent
- People vs. persons
- Per diem
- Per se
- Percent vs. per cent
- Perchance
- Perfect storm
- Period
- Periodic vs. periodical
- Pernickety vs. persnickety
- Perquisite vs. prerequisite
- Persecute vs. prosecute
- Persona non grata
- Peruse
- Pervade throughout
- Phenomena and phenomenon
- Phony vs. phoney
- Phrasal adjectives
- Phrasal prepositions
- Phrasal verbs
- Phrases
- Picaresque vs. picturesque
- Pincer vs. pincher
- Plain vs. plane
- Plainclothes
- Plan ahead, plan in advance
- Playwright or playwrite?
- Pleaded vs. pled
- Plenitude vs. plentitude
- Plethora
- Plough vs. plow
- Plum vs. plumb
- Point in time
- Point of view, standpoint, and viewpoint
- Poisoning the well
- Polemic, polemical
- Politics
- Pollyanna
- Polygamy, polygyny, polyandry
- Pompom, pompon, and pom-pom
- Ponderous
- Populous, populace, and population
- Pore over vs. pour over
- Port, starboard
- Portend, portent
- Possessive nouns
- Poster child
- Postpositive adjectives
- Potentiality
- Practical vs. practicable
- Practice vs. practise
- Pray vs. prey
- Pre-plan
- Precede vs. proceed
- Predicate adjectives
- Predicate nominatives
- Premier vs. premiere
- Preposition vs. proposition
- Prepositional objects
- Prepositions
- Prescribe vs. proscribe
- President
- Presumptive vs. presumptuous
- Pretence vs. pretense
- Preventative vs. preventive
- Principle vs. principal
- Prior experience
- Prior, previous
- Privacy policy
- Proactive
- Problematic vs. problematical
- Proceed forward
- Procrastinate
- Prodigal son
- Program vs. programme
- Pronouns
- Proof by example
- Proof positive
- Proper adjectives
- Prophecy vs. prophesy
- Proportional vs. proportionate
- Prospective vs. perspective
- Prostate vs. prostrate
- Protagonist and antagonist
- Protégé
- Proved vs. proven
- Psych vs. psyche
- Psychiatry vs. psychology
- Pull the rug out from under
- Pullout, pull-out, and pull out
- Purposely vs. purposefully
Q
- Qualitative and quantitative
- Qualitative vs. qualitive
- Quantitative vs. quantitive
- Quash vs. squash
- Quasi
- Question mark
- Quid pro quo
- Quotation marks
R
- Rack vs. wrack
- Racket vs. racquet
- Radical
- Raison d'etre
- Rappel vs. repel
- Rapt vs. wrapt
- Raring to
- Rate of speed
- Ravaging vs. ravishing
- Re-create vs. recreate
- Reactionary and reactive
- Realise vs. realize
- Reappropriate
- Rearranging the deck chairs on the Titanic
- Recur vs. reoccur
- Red herring
- Regard vs. regards
- Regime vs. regimen
- Regrettable vs. regretful
- Relevance vs. relevancy
- Remunerate vs. renumerate
- Repay back
- Repel vs. repulse
- Resilience vs. resiliency
- Respective, respectively
- Restaurateur
- Restrictive and nonrestrictive
- Retard
- Retch vs. wretch
- Return back
- Ridded
- Rife vs. ripe
- Riff vs. rift
- Riffraff
- Right-of-way
- Righten
- Ring vs. wring
- Rock 'n' roll, rock and roll, rock'n'roll, etc.
- Rogue vs. rouge
- Role vs. roll
- Rollout vs. roll out
- Rollover vs. roll over
- Root vs. route
- Row to hoe
- Rubenesque
- Rule of thumb
- Rumor vs. rumour
- Run-on sentences
- Runaway vs. run away
- Résumé
S
- Saccharin vs. saccharine
- Sacrilege, sacrilegious
- Safe-deposit box or safety-deposit box?
- Said
- Saltwater vs. salt water
- Sans
- Savanna vs. savannah
- Savior vs. saviour
- Sceptic vs. skeptic
- Schadenfreude
- Scissors
- Scuttlebutt
- Seasons (capitalization)
- Secede vs. succeed
- Secret vs. secretive
- Seldomly
- Semicolon
- Sensual vs. sensuous
- Sentence-ending prepositions
- Sentences
- Sentient
- Series
- Service (as a verb)
- Sew vs. sow
- Shat, shitted
- Shaved vs. shaven
- Sheath vs. sheathe
- Shedded
- Shelf vs. shelve
- Sherbet vs. sherbert
- Shined vs. shone
- Shoo-in
- Short shrift
- Showrunner
- Sic
- Sic vs. sick
- Sight vs. site
- Silicon vs. silicone
- Simple sentences
- Sine qua non
- Skilful vs. skillful
- Sleight of hand
- Slight edge
- Slight hint
- Smelled vs. smelt
- Smite, smote, smitten
- Smoothe, smoothen
- Smorgasbord
- Sneaked vs. snuck
- So to speak
- Software program
- Soldiers, marines, airmen, and sailors
- Somber vs. sombre
- Some odd
- Somebody and someone
- Someday vs. some day
- Someplace vs. some place
- Somersault
- Sometime vs. some time
- Someway
- Sooner rather than later
- Sort of
- Soup up
- Sow wild oats
- Spaces between sentences
- Spatter vs. splatter
- Speak to
- Speciality vs. specialty
- Species
- Specter vs. spectre
- Spectra vs. spectrums
- Sped vs. speeded
- Spelled vs. spelt
- Spendthrift
- Spilled vs. spilt
- Spitting image
- Split infinitives
- Spoiled vs. spoilt
- Spreaded
- Spur vs. spurn
- Squelch vs. quelch
- Stadiums or stadia?
- Stained glass or stain glass?
- Stalactite and stalagmite
- Stanch vs. staunch
- Standby vs. stand by
- Stank
- Stanza
- Star-crossed
- State of the art
- Stationary vs. stationery
- Status quo
- Statute of limitations
- Steady stream
- Sticktoitiveness
- Stock, shares
- Storey vs. story
- Straight vs. strait
- Strait-laced or straight-laced?
- Straitjacket
- Strategy vs. stratagem
- Straw man fallacy
- Subconscious vs. unconscious
- Subjects and predicates
- Subjunctive mood
- Substantial vs. substantive
- Subtle vs. subtil
- Suffice it to say
- Suffixes
- Sui generis
- Sum total
- Summons and summonses
- Supposably
- Supposed to
- Surveil
- Swath vs. swathe
- Sweated
- Sworn affidavit
- Synecdoche
- Synonyms
- Systematic vs. systemic
T
- T-shirt, t-shirt, tee-shirt, and tee shirt
- T.E. Hulme: Romanticism and Classicism
- Tack vs. tact
- Tail vs. tale
- Take into consideration
- Takeaway and takeout
- Taken aback
- Teeth vs. teethe
- Teetotaler
- Telegram vs. telegraph
- Tenant vs. tenet
- Terminate
- Terza rima
- Testament vs. testimony
- Textish
- Than vs. then
- That vs. which
- That vs. who
- That which
- The $64,000 question
- The Bronx
- The late
- The rub
- Theater vs. theatre
- Their, there, they're
- Theory
- Therefore
- They vs. he or she
- Tho and altho
- Through vs. thru
- Throw under the bus
- Thrust, thrusted
- Thusly
- Tic vs. tick
- Tidbit vs. titbit
- Timber vs. timbre
- Timeout vs. time out
- Tire vs. tyre
- Title capitalization
- To a T
- To boot
- To vs. too
- To wit
- Toe the line
- Toilette
- Tolerance vs. toleration
- Ton vs. tonne
- Tongue-in-cheek
- Topography vs. typography
- Torturous vs. tortuous
- Toward vs. towards
- Toxicology vs. toxology
- Transgender, transsexual, transvestite
- Translucent vs. transparent
- Transpire
- Transport vs. transportation
- Trawl vs. troll
- Treasurys
- Triple vs. treble
- Trochee
- Troop vs. troupe
- Truck with
- Trustee vs. trusty
- Tsk-tsk
- Turbid, turgid, torpid
- Turtle, tortoise, and terrapin
U
- U.S. state demonyms
- Uber
- Unawares
- Uncomparable adjectives
- Underwater vs. under water
- Underway vs. under way
- Undoubtably
- Unique
- United States (plural or singular?)
- Unkempt and unkept
- Unknown quantity
- Until, till, and 'til
- Untoward
- Up to date
- Up until
- Upfront vs. up front
- Upmost vs. utmost
- Usage vs. use
- Used to
- Usually always
V
- Vagina vs. vulva
- Vain, vein, and vane
- Vamoose
- Vapid vs. vacuous
- Various different
- Verbiage
- Verbs
- Verses vs. versus
- Vertex vs. vortex
- Very
- Vice versa
- Vice vs. vise
- Vicious vs. viscous
- Virgule
- Vis-a-vis
- Viz.
- Voicemail
- Voilà
- Vouchsafe
W
- Wack vs. whack
- Waddle vs. wattle
- Wagon vs. waggon
- Waive vs. wave
- Waiver vs. waver
- Wander vs. wonder
- Wane, wax
- Wanton vs. wonton
- Warrantee vs. warranty
- Wary vs. weary
- Weaved, wove, and woven
- Web site or website?
- Website, web page
- Well respected
- Well-heeled
- Welsh
- Wet vs. whet
- Whac-A-Mole
- Whatnot
- Whence vs. from whence
- Whereas
- Whether or not
- While at the same time
- While away or wile away?
- Whilst
- Whiny, whiney, whinny, Whinney
- Whiskey vs. whisky
- Whither
- Who vs. whom
- Who's vs. whose
- Who's Who
- Whoever vs. whomever
- Whole entire
- Whoop, whup
- Widow and widower
- Wilful vs. willful
- Winningest
- Wit vs. whit
- With the exception of
- Wont
- Workout vs. work out
- Worse comes to worst
- Wreak havoc
- Wreath vs. wreathe
- Write-off vs. write off
- Wrong vs. wrongly
- Wunderkind
Y
- Y'all
- Yogurt vs. yoghurt
- Yoke vs. yolk
- You (in formal writing)
- Your vs. you're
Z
- Zee vs. zed
- Zeitgeist