- sacrilegious
- safety
- sandwich
- schedule
- science
- scream
- screech
- seems
- seize
- sense
- sentence
- separate
- sergeant
- several
- shiftless
- shining
- shone
- shown
- shriek
- siege
- similar
- since
- smooth
- soliloquy
- sophomore
- speak
- specimen
- speech
- statement
- stationary
- stationery
- statue
- stature
- statute
- steal
- steel
- stops
- stopped
- stopping
- stories
- stretch
- strictly
- succeeds
- successful
- summarize
- superintendent
- supersede
- sure
- surprise
- syllable
- symmetrical
- temperament
- tendency
- than
- their
- there
- therefore
- they're
- thorough
- thousandths
- till
- to
- too
- together
- tragedy
- track
- tract
- transferred
- tranquillity
- translate
- treacherous
- treasurer
- tries
- trouble
- truly
- Tuesday
- two
- typical
- tyranny
- universally
- until
- using
- usually
- vacancy
- vengeance
- vigilance
- village
- villain
- weak
- wear
- weather
- Wednesday
- week
- weird
- welfare
- where
- wherever
- whether
- which
- whole
- wholly
- who's
- whose
- wintry
- wiry
- within
- without
- women
- world
- writing
- written
- your
- you're
[Note 1.]—The following words have more than one correct form, the one given here being preferred.
- abridgement
- acknowledgment
- analyze
- ax
- boulder
- caliber
- catalog
- center
- check
- criticize
- develop
- development
- dulness
- endorse
- envelop
- esthetic
- gaiety
- gild
- gipsy
- glamor
- goodby
- gray
- inquire
- medieval
- meter
- mold
- mustache
- odor
- program
- prolog
- skilful
- theater
[Note 2.]—In a few groups of words American spelling and English spelling differ. American spelling gives preference to favor, honor, labor, rumor; English spelling gives preference to favour, honour, labour, rumour. American spelling gives preference to civilize, apprize; defense, pretense; traveler, woolen; etc. English spelling gives preference to civilise, apprise; defence, pretence; traveller, woollen; etc.