Excerpted from: You’re Doing It Wrong: Dump the Myths, Misconceptions and Bad Advice You Believe

I use words for a living and even I was surprised to dig into this topic and learn the true meaning of words we use:

Discreet vs. Discrete: careful vs separate.

Nonplussed: means bewildered, not unbothered.

Fortuitous: means by chance; not always fortunate. Which mean it could be bad.

Enormity: In strict formal and literary contexts, it refers to a grave, monstrous, or immoral act, or the quality of being utterly evil. Most of us use it informally: it is used to describe a vast, staggering, or overwhelming size, extent, or momentousness.

Literally: Often misused to mean “figuratively”.

Disinterested: means neutral, not uninterested.

Ultimate: means last, not the best.

Bemused: means confused, not amused.

Ironic: not just coincidental but the opposite of expectation.

Peruse: mean read carefully; not skim.

Decimate: originally meant one in ten— A form of extreme punishment in the Roman Army where a unit that had exhibited cowardice or some other extreme behavior would be punished by having 1 in 10 members randomly chosen and executed. We use it often to mean destroy everything.

Momentarily: means for a moment. Not in a moment.

Fewer vs. less: fewer for countable things (fewer cookies), less for uncountable (less sugar).

Comprise vs. compose: the whole comprises the parts; the parts compose the whole. “Is comprised of” is technically incorrect, though common. Yeah. Read that one again.

Then there are these editor favorite ones to correct:

affect / effect Affect is usually a verb meaning to influence: “The weather affected my mood.” Effect is usually a noun meaning the result: “The weather had an effect on my mood.” The trick is that each has a less common flip side. Effect can be a verb meaning to bring about (“to effect change”), and affect can be a noun in psychology meaning observable emotion (“a flat affect”). But 95% of the time, affect = verb, effect = noun.

its / it’s Its is possessive: “The dog wagged its tail.” It’s is a contraction of “it is” or “it has”: “It’s raining.” The confusion comes because we usually add apostrophe-s to show possession, but possessive pronouns (its, his, hers, theirs) never take an apostrophe. Test: if you can swap in “it is,” use it’s.

who’s / whose Same logic as above. Who’s is a contraction of “who is” or “who has”: “Who’s coming to dinner?” Whose is possessive: “Whose coat is this?” Test: if “who is” fits, use who’s.

complement / compliment A complement completes something or goes well with it: “The wine complements the meal.” A compliment is praise: “She gave me a compliment.” Memory aid: complement has an e like complete; a compliment is something I like to receive.

principal / principle Principal as a noun is a person in charge (school principal) or a sum of money (the loan’s principal); as an adjective it means main or primary (“the principal reason”). A principle is a rule, belief, or fundamental truth (“moral principles”). Memory aid: the principal is your pal, and a principle is a rule (both end in -le).

lay / lie Lay means to put or place something down and takes a direct object: “Lay the book on the table.” Lie means to recline and takes no object: “I’m going to lie down.” The real headache is the past tense: the past of lie is lay (“Yesterday I lay down”), which is exactly the same as the present tense of the other verb. And the past of lay is laid (“I laid the book down”). So:

• Today I lie down / Yesterday I lay down / I have lain down

• Today I lay the book down / Yesterday I laid it down / I have laid it down