Commonly confused words
Some word pairs look or sound alike but mean different things.
Updated October 29, 2026
The rule
Affect is usually the verb (the rain affected the game); effect is usually the noun (the rain had an effect). Then is about time; than compares. Accept means to receive; except means leaving out. Lose means to misplace; loose means not tight.
Principal is the head of a school or the main thing; principle is a rule or belief. Complement completes; compliment praises.
Examples
The medicine had a strong affect.The medicine had a strong effect.She is taller then her sister.She is taller than her sister.
Quick test: Swap in the meaning: "had a strong result" works, so it is effect, the noun.
Try it: find the mistake
The mistake in each sentence is highlighted. Say the fix out loud, then open the answer.
I ate more cookies then my brother.
I ate more cookies than my brother.
Than compares; then is about time.
Don't loose your ticket.
Don't lose your ticket.
Lose means to misplace; loose means not tight.
The cold weather will effect the harvest.
The cold weather will affect the harvest.
Here the word is a verb (will ___), so it is affect.
Everyone accept Jordan finished the race.
Everyone except Jordan finished the race.
Except means "all but"; accept means to receive.
Where this rule is tested
Questions people ask
What is the rule for commonly confused words?
Some word pairs look or sound alike but mean different things. Affect is usually the verb (the rain affected the game); effect is usually the noun (the rain had an effect). Then is about time; than compares. Accept means to receive; except means leaving out. Lose means to misplace; loose means not tight.
How can I check my commonly confused words quickly?
Swap in the meaning: "had a strong result" works, so it is effect, the noun.
Where can I practice this for free?
In Owl Test Prep's Daily Grammar Fix: one sentence a day for everyone, plus practice sets of five on this rule. It is free, with no account.