Grammar Errors by Seriousness

Common grammar errors listed by their ability to make you look stupid

Some grammar errors are more embarrassing than others. The list below starts with the ones that will make you look stupid and ends with the ones that you'll probably get away with. You can use this list to prioritize how you read the free lessons and tests on our site.
"In business, you are what you write."

Mistakes that will make you look really stupid

Confusing you're and your
Confusing its and it's
Using an apostrophe in a plural (e.g. 4 lion's)
Writing could of, would of or should of
Confusing too and to
Confusing they're, their and there
Confusing who's and whose
Using a double superlative or comparative (e.g. most prettiest, more better)
Confusing accept and except
Writing her's, our's or their's
Confusing allot, a lot and allot or writing alot
Confusing allowed and aloud
Confusing desert and dessert
Confusing grisly and grizzly
Confusing then and than

Mistakes that will make you look careless

Confusing advice and advise
Confusing e.g. and i.e.
Confusing affect and effect
Getting an or a wrong
Confusing adverse and averse
Putting a capital letter on a common noun (e.g. Drink our Water)
Confusing allude and elude
Confusing allusion and illusion
Confusing altar and alter
Confusing bare and bear
Confusing being or been
Confusing censor, censure and sensor
Confusing cite, sight and site
Confusing coarse and course
Using a dangling modifier (e.g. Smelly and heavy, she prodded the walrus.)
Confusing decent, descent and dissent
Confusing defuse and diffuse
Confusing elicit and illicit
Confusing fewer and less
Confusing forth and fourth
Confusing imply and infer
Confusing incite and insight
Confusing loose and lose
Confusing past or passed
Confusing plain and plane
Confusing pore, pour and poor
Wrongly placed apostrophe for possession (e.g. The cat bit the dogs' leg.)
No subject and verb agreement (e.g. A box of tapes are under the stairs.)
Confusing principal and principle
Confusing precede and proceed
Confusing raise, rise and raze
Confusing role and roll
Confusing colons and semicolonswhen extending a sentence
Confusing stationary and stationery
Writing these kind of and not these kinds of
Confusing vain, vein and vane
Confusing waist and waste
Confusing weather, whether and wether

Mistakes for which you'll be forgiven

Being inconsistent with abbreviations (e.g. BBC and I.T.V.)
Putting AD after the year (e.g. 2011 AD)
Confusing adoptive and adopted
Failing to use hyphens in compound adjectives (e.g. 4 seater aircraft)
Confusing already or all ready
Using "my wife and I" when you mean "me and my wife"
Confusing appraise and apprise
Confusing beside and besides
Confusing breathe and breath
Continuing a sentence with , however,
Confusing climactic and climatic
Failing to use a comma after a transitional phrase (e.g. As a result he lost.)
Not knowing when to use a comma before which and who
Confusing complement and compliment
Confusing definite and definitive
Confusing dependant and dependent
Confusing discreet and discrete
Confusing disinterested and uninterested
Creating a double negative with neither/nor
Confusing incidence and incidents
Confusing instance and instants
Confusing law and lore
Confusing lay and lie
Confusing lead and led
Confusing licence or license
Confusing loath and loathe
Confusing notable and noticeable
Confusing practice or practise
Confusing precedence and precedent
Confusing prophecy and prophesy
Confusing proscribe and prescribe
Starting a sentence with which or who (e.g. She can play the trumpet. Which is nice.)
Confusing storey and story
Confusing who and whom

Mistakes you'll probably get away with

Failing to use hyphens in expressions like "3-and-a-quarter million"
Using hyphens with adverbs (e.g. extremely-talented actor)
Confusing alright or all right
Confusing altogether and all together
Confusing amoral and immoral
Confusing amount, quantity and number
Failing to use apostrophes in temporal expressions (e.g. 3 years insurance)
Using a capital letter for a season (e.g. next Summer)
Confusing can and may
Confusing canvas and canvass
Failing to use a comma after an interjection (e.g. Yes I do.)
Failing to use a comma to show the vocative case (e.g. John you're next.)
Confusing compose and comprise
Writing comprise of
Using a hyphen instead of a dash
Confusing economic and economical
Confusing enquiry and inquiry
Confusing envelop and envelope
Confusing getaway and get away
Confusing historic and historical
Confusing if and whether
Using the wrong version of into/in to, onto/on toand up to
Putting a hyphen in no one(e.g. no-one)
Incorrectly writing numbers in full
Confusing provided or providing
Illogically placing punctuation inside or outside a quotation
Failing to nest quotation marks (singles and doubles) correctly
Starting sentences with figures

"Mistakes" that might annoy your reader

Ending a sentence in a preposition
Using a split infinitive (e.g. to really try)
Starting a sentence with And or But
Not using a comma before and when merging two sentences
Putting a full stop (period) after a contraction (e.g. Mr.)
Failing to use a comma after a sentence introduction (e.g. At 4 o'clock he went home.)
Not following your national convention with commas in lists
Incorrectly treating a collective noun as singular or plural
Using a comma after long subject of a sentence
Treating none as a plural word
See also:

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