accept/exceptUse 'accept' with an 'a' as a verb meaning 'to take.' Use 'except' with an 'e' as a preposition meaning 'other than.'
advice/advise/informUse 'advice' as a noun and 'advise' as a verb. Unless actually offering advice, use 'inform.'
a lot / allotSpell 'a lot' as two words; 'alot' is not a word. Use 'allot' as a verb meaning to distribute.
a part / apartSpell 'a part' as two words meaning a piece of something. Spell 'apart' as one word meaning separated.
alumni, alumnus, alumna, alumnae Use 'alumnus' for a male, 'alumna' for a female, 'alumnae' for females, and 'alumni' for males.
anxious/eagerUse 'anxious' to imply anxiety and a negative feeling. Use 'eager' for a positive feeling.
beside/besidesUse 'beside' to mean 'next to' and 'besides' to mean 'except' or 'also.'
between/among Use 'between' for two things and 'among' for three or more.
breath/breatheUse 'breath' as a noun and 'breathe' with an e as a verb.
complement/complimentUse 'complement' with an 'e' for things that go together well or match.Use 'compliment' with an 'i' for a flattering comment.Use 'complimentary' with an 'i' for things that are free of charge.
conscience/consciousUse 'concsience' to mean 'a sense of right and wrong' and 'conscious' to mean 'aware or deliberate.'Do not confuse 'conscience' with 'consciousness.'
dessert/desertUse 'dessert' with a double 's' for an after-dinner meal or delicious food. Use 'desert' with one 's' for a dry location, as a verb meaning 'to abandon' (as if in a desert).The phrase 'just deserts' (what is justly deserved) has one 's.'
different from/different thanUse 'different from' instead of 'different than.'
effect/affect Use 'effect' with an 'e' as a noun and 'affect' with an 'a' as a verb, with the following exceptions:
e.g./i.e.Use 'e.g.,' before a list of examples and 'i.e.,' before a clarification or restatement.
ensure/insureUse 'insure' with an 'i' only in relation to insurance.
farther/further Use 'farther' for physical distance and 'further' for time, amount, or intensity.
good/wellUse 'good' as an adjective and 'well' as an adverb (a good dog that hunts well).In usage meaning healthy or fine, 'to feel well' and 'to feel good' are both acceptable.
hers/hisDo not put an apostrophe in the words 'hers' or 'his' (This jackets is hers).
historic/historicalUse 'historic' to imply importance and 'historical' for things related to history or time.
in/duringUse 'in' for physical proximity and 'during' for time (during the 80s).
it’s/itsUse 'it’s' with an apostrophe to mean 'it is' (It’s a terrible shame). Use 'its' without an apostrophe as a possessive (Its color is faded).
lay/lieUse 'lay' when a noun follows (Chickens lay eggs.) and 'lie' in the expression 'to lie down.'In the past tense, 'lay' becomes 'laid' (not 'layed') and 'lie down' becomes 'lay down' or 'had lain down.'
less/fewerUse 'fewer' for items that can be counted individually (fewer coins, less money).
many/muchUse 'many' for items that can be counted individually (many storms, much bad weather).
may/mightUse 'may' for permission and 'might' for possibility.
more/higher/above/overReplace 'higher,' 'above,' 'over,' and other physical descriptions with 'more' for amounts.
of/haveUse 'have' and not 'of' in phrases like 'must have' or 'could have.'
on/aboutUse 'on' for physical proximity and 'about' to mean 'concerning' or 'related to.'
once/whenReplace 'once' with 'when' if it cannot be changed to 'one time' and still make sense.
principle/principalUse 'principle' with an le 'as' a noun for a law or standard.Use 'principal' with an 'al' as an adjective meaning important or as a noun (principal of my school).
since/becauseUse 'since' to mean a timeframe and 'because' to mean cause and effect.
then/thanUse 'than' for comparisons only (more than, better than, rather do this than that).
there/they’re/theirUse 'they’re' with an apostrophe to mean 'they are.' Use 'their' as a possessive (their house).
there’s/theirsUse 'there’s' with an apostrophe to mean 'there is.' Use 'theirs' as a plural possessive (it is theirs).
thru/throughUse 'through' instead of 'thru' in formal writing.
who’s/whoseUse 'who’s' with an apostrophe to mean 'who is' (Who’s the boss?).Use 'whose' without an apostrophe as a possessive (Whose line is it?).
you’re/yourUse 'you’re' to mean 'you are' and 'your' as a possessive (You’re wearing your new hat).
yours and oursDo not use an apostrophe in 'yours' or 'ours' as possessives (They’re all yours).