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Grammar and Usage Unit 5: Commonly confused words

Many errors come from words that sound alike. A quick test for each pair fixes most mistakes.

Covers: their/there/they're, your/you're, affect/effect, then/than, to/too/two, accept/except, lose/loose

Study guide

Many common errors come from words that sound alike but mean different things. The best strategy is to test each one by its meaning or by expanding contractions.

Their, there and they're: their shows possession (their car), there points to a place or begins a sentence (over there, there are), and they're means "they are." Your and you're: your shows possession (your book), and you're means "you are." Its and it's work the same way: its is possessive, and it's means "it is" or "it has."

Affect and effect: affect is usually a verb meaning to influence (the weather affects my mood), and effect is usually a noun meaning a result (the weather had an effect). The less common uses are effect as a verb meaning to bring about (to effect change) and affect as a noun in psychology.

Then and than: then refers to time or sequence (we ate, then left), and than makes comparisons (taller than me).

To, too and two: to shows direction or begins an infinitive (go to school, to run), too means also or excessively (me too, too hot), and two is the number.

Accept and except: accept means to receive or agree (accept an award), and except means excluding (everyone except me).

Lose and loose: lose means to misplace or fail to win, and loose means not tight.

Other common pairs include who's (who is) and whose (possessive), principal (main or a school leader) and principle (a rule), and complement (completes) and compliment (praise). Also, "should of" is always wrong; it's "should have" or "should've."

Lie means to recline and takes no object (lie, lay, lain: "I lay down yesterday"). Lay means to put something down and needs an object (lay, laid, laid: "She laid the book on the table"). Sit and set follow the same pattern: you sit down, but you set something down. A speaker or writer implies, or suggests, something without saying it outright. A listener or reader infers, or draws a conclusion, from what was said. "Her tone implied she was angry, so I inferred I should leave."

Precede means to come before ("A speech preceded the dinner"), and proceed means to go forward or continue ("Please proceed to the gate"). Formally means in a formal way, and formerly means previously ("She was formerly a teacher"). You emigrate from a country and immigrate to a new one. Beside means next to ("Sit beside me"), and besides means in addition to or except ("Besides math, I take art").

Also learn idea (a thought) versus ideal (a perfect standard), dyeing (coloring) versus dying (ceasing to live), fewer (countable things) versus less (amounts), between (two) versus among (three or more), and farther (physical distance) versus further (degree or extent).

Key ideas

• their (belonging to them), there (place), they're (they are).
• your (belonging to you), you're (you are).
• affect is usually a verb; effect is usually a noun.
• than compares; then shows time.
• to (direction), too (also/excessively), two (2).

Formulas and rules

Common mistakes

• Writing "should of" instead of "should have".
• Using "loose" (not tight) when you mean "lose".

Words to know

they're

they are

affect vs effect

Affect is usually a verb; effect is usually a noun.

then vs than

Then is time; than compares.

accept vs except

Accept = receive; except = excluding.

lose vs loose

Lose = misplace or fail to win; loose = not tight.

Contraction test

Expand it to check: they're → they are.

their

Possessive: belonging to them.

there

A place, or a sentence starter (there are).

your vs. you're

Possessive / you are.

its vs. it's

Possessive / it is or it has.

to vs. too vs. two

Direction / also or excessively / the number 2.

who's vs. whose

Who is / possessive.

principal vs. principle

Main or a school leader / a rule or belief.

complement vs. compliment

Completes something / praise.

"should of"

Always wrong; use should have or should've.

Sample practice questions

29 more questions like these, from level 1 to 5, are in the practice set.