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Contributors: Purdue OWL.

This resource covers common spelling errors including accept/except, ei/ie, noun plurals, and –ible/able.

Spelling: Common Words that Sound Alike

Many words sound alike but mean different things when put into writing. This list will help you distinguish between some of the more common words that sound alike. Click on any of the blue underlined links to open a longer and more complete definition of the word in a new window.

Forms to remember

Accept, Except

We are currently updating these resources, but for more information on these words, plus exercises, see our document on accept and except.

Affect, Effect

A memory-aid for affect and effect is RAVEN: Remember, Affect is a Verb and Effect is a Noun.

We are currently updating these resources, but for more information on these words, plus exercises, see our document on affect and effect.

Advise, Advice

Conscious, Conscience

Idea, Ideal

Its, It's

Lead, Led

Than, Then

Than used in comparison statements: He is richer than I.
used in statements of preference: I would rather dance than eat.
used to suggest quantities beyond a specified amount: Read more than the first paragraph.
Then a time other than now: He was younger then. She will start her new job then.
next in time, space, or order: First we must study; then we can play.
suggesting a logical conclusion: If you've studied hard, then the exam should be no problem.

Their, There, They're

To, Too, Two

Two, twelve, and between are all words related to the number 2, and all contain the letters tw.

Too can mean also or can be an intensifier, and you might say that it contains an extra o ("one too many")

We're, Where, Were

Your, You're

I/E Rule

Write I before E

Except after C

Or when it sounds like an A

As in "neighbor" and "weigh"

i before e: relief, believe, niece, chief, sieve, frieze, field, yield

e before i: receive, deceive, ceiling, conceit, vein, sleigh, freight, eight


seize, either, weird, height, foreign, leisure, conscience, counterfeit, forfeit, neither, science, species, sufficient

Please see our exercises to practice these rules. 

-ible, -able Rule

-ible -able
If the root is not a complete word, add -ible.

aud + ible = audible

  • visible
  • horrible
  • terrible
  • possible
  • edible
  • eligible
  • incredible
  • permissible
If the root is a complete word, add -able.

accept + able = acceptable

  • fashionable
  • laughable
  • suitable
  • dependable
  • comfortable

If the root is a complete word ending in -e, drop the final -e and add -able.

excuse - e+ able = excusable

  • advisable
  • desirable
  • valuable
  • debatable

Some exceptions:

Try some exercises for spelling -ible and -able correctly.

Please note we are in the process of revising our exercises. They will eventually be altered to reflect those revisions.