English has a lot of commonly confused words. They either look alike, sound alike or, worst of all, look and sound alike but have completely different meanings. Other words look and sound different but are similar in meaning, and it's hard to determine which is the correct one in a given context. Hopefully the following list of pairs of commonly confused words will help you keep them straightened out.
Accept (verb) - to receive
Except (conjunction) - apart from; otherwise than; were it not true
Affect (verb) - to have an effect on; influence; produce a change in; to stir the emotions
Effect (noun) - anything brought about by a cause or agent; result
"All intensive purpose" is an incorrect use of the phrase "all intents and purposes."
"All intents and purposes" is a phrase that means "for all practical purposes" or "under most usual situations."
A lot (noun phrase) -many
*"A lot" is always two separate words. "Alot" is not a real word.
Allot (verb) - to distribute, give or assign
Allusion (noun) - an indirect reference
Illusion (noun) - a false idea or conception; belief or opinion not in accord with the facts; an unreal, deceptive, or misleading appearance or image
Awhile (adverb) - for a while; for a short time
A while (noun) - for a short time; when while is used as the object of the preposition (for a while) then the "a" is separated from the "while"
Bad (adjective) - not good
Badly (adverb) - not well; in a bad manner; harmfully; incorrectly; wickedly; unpleasantly
*Here, a note. Adjectives generally describe nouns, so even if you use the word "bad" following a verb in a sentence, if it's meant to describe the thing itself, then use the adjective. "Bad" here means the same as "rotten," "rancid" or "stinky," all of which are adjectives. If you can replace "bad" with another adjective and still have a sentence that makes sense, then you know that "bad" was the correct choice. Adverbs often describe the manner in which something is done. To say, "your feet smell badly" is to say that your feet are inhaling through the nose and perceiving odors, and that they're going about it all wrong.
Borrow (verb) - to take or accept something for a short time with the intention of returning it to its rightful owner
Lend (verb) - to give something for a short time with the intention of getting it back
Breath (noun) - air taken into the lungs and then let out
Breathe (verb) - to inhale and exhale
Butt Naked is a phrase that means to be without clothes.
Buck Naked is a phrase that also means to be naked and without clothing.
*Note - Neither of these phrases is incorrect. The term buck naked may derive from the term buckskin, that which hides are fashioned. However, neither term has much etymological backing for one being more correct than another.
Cache (noun) - a safe place to store supplies; anything stored or hidden in such a place
Cash (noun) - money, coins, bills; currency
Chomp at the bit - an over used and incorrect form of "champing at the bit"
Champ at the bit (idiom) - ready or anxious; eager to be going or moving along.
Complement (noun) - that which completes or brings to perfection; (verb) - to make complete
Compliment (noun) - something said in admiration, praise, or flattery; (verb) - to pay a compliment to; congratulate
Comprise (verb) - to include; to contain; to consist of; to be composed of
Compose (verb) - to form in combination; make up; constitute
Desert (verb) - to forsake or abandon; to leave without permission; to fail when needed
Desert (noun) - dry, barren, sandy region
Dessert (noun) - a sweet course served at the end of a meal
Done (adjective) - completed; sufficiently cooked; socially acceptable
Done (verb) - the past participle of do
Did (verb) - past tense of do
Elicit (verb) - to draw forth; evoke
Illicit (adjective) - unlawful; illegal
Fair to midland - an incorrect use of the phrase "fair to middling"
Fair to middling (phrase) - something that is moderate to average in quality
Had Bought (verb) - the past perfect tense of the verb buy
Had Boughten - incorrect usage of the past perfect tense
Hone (verb) - to sharpen; to yearn or long for; to grumble or moan
Home (noun) - dwelling; place where a person lives
Idiosyncrasy (noun) - any personal peculiarity or mannerism; individual reaction to food or drug.
Idiosyncracy is a misspelling of idiosyncrasy.
Imitated (verb) - past tense of the verb imitate, which means to seek to follow the example of; impersonate; mimic
Intimated (verb) - to make known indirectly; to hint or imply
In a sense (idiom) - in a way; in one way of looking at it
In essence (idiom) - by nature; essentially
In one foul swoop - an incorrect use of the phrase "in one fell swoop"
In one fell swoop - a phrase meaning "all at once"
Its (possessive pronoun) - of, belonging to, made by, or done by it
It's (contraction) of it + is
I could of - an incorrect use of the verb phrase could have; when written as a contraction "could've" sounds like "could of."
I could have - is the past perfect tense of the verb could
I should of - an incorrect use of the verb phrase should have; when written as a contraction "should've" sounds like "should of."
I should have - is the past perfect tense of the verb should
I would of - an incorrect use of the verb phrase would have; when written as a contraction "would've" sounds like "would of."
I would have - is the past perfect tense of the verb would
Lead (noun) - a heavy, soft, malleable, bluish-gray metallic chemical element used in batteries and in numerous alloys and compounds
Led (verb) - past tense and past participle of the verb "to lead"
Lose (verb) - to become unable to find; to mislay; to fail to win or gain
Loose (adjective) - not tight; giving enough room
More/most importantly - a phrase used often in writing to show emphasis; however, many grammarians insist that this is not correct usage. The adverbial ending of -ly is not needed.
More/most important - this phrase should be used instead
Passed (verb) - past tense of the verb "to pass"
Past (adjective) - of a former time; bygone; (noun) - the time that has gone by; days, months, or years gone by
Precede (verb) - to be, come, or go before in time, place, order, rank, or importance
Proceed (verb) - to advance or go on, especially after stopping
Principal (noun) - a governing or presiding officer, specifically of a school; (adjective) - first in rank, authority, importance, degree, etc.
Principle (noun) - a fundamental truth, law, doctrine, or motivating force, upon which others are based
Seen (verb) - past participle of the verb see; must be used with the verbs has, have, or had
Saw (verb) - past tense of the verb see
Sell (verb) - to give up, deliver or exchange for money
Sale (noun) - the act of selling; the work, department, etc. of selling
Sight (noun) - something seen, a view, field of vision
Site (noun) - a piece of land considered for a specific purpose
"Spitting image" is a phrase that means exactly like. The first known use in writing of this phrase was in 1901.
"Spirit and Image" - There is some speculation that the "spit" in the phrase "spitting image" came from the word "spirit" in the phrase "spirit and image." However, there is no etymological basis for this belief since the phrase "spirit and image" used in reference to an exact likeness is not found in writing. The terms "spit," "spit and image," and "dead spit" have all been found to refer to a likeness since the 1800's.
Stationary (adjective) - not moving or not movable; fixed or still
Stationery (noun) - writing materials; specifically, paper and envelopes used for letters
Taut (adjective) - tightly stretched; showing strain; tidy or well-disciplined
Taunt (verb) - to reproach in scornful or sarcastic language; to drive or provoke
Than (conjunction) - used to introduce the second element in a comparison
Then (adverb) - at that time; next in order; (adjective) - of that time; (noun) - that time
Their (adjective) - of, belonging to, made by, or done by them
There (noun) - that place or point
They're (contraction) of they + are
To (preposition) - in the direction of and reaching; as far as; to the extent of
Too (adverb) - in addition; as well; besides; also; more than enough; superfluously; overly; to a regrettable extent; extremely
Two (adjective) the number 2
Your (adjective) - belonging to you
You're (contraction) - you are
Who (subject pronoun) - what or which person or persons; the person or persons that, or a person that (used to introduce a relative clause)
Whom (object pronoun) - what or which person or persons; the person or persons that, or a person that (used to introduce a relative clause)
If you have questions or doubts about these (or any other) commonly confused words and how to use them correctly, you can consult the "usage examples" section of each word's definition page on YourDictionary.com.