Sentence Craft · Correctness
Commonly confused words
its/it's, affect/effect, fewer/less, then/than, principal/principle: fix the errors readers notice first.
Step 1 of 4 · Overview15 min read ·
| Pair | Rule | Example |
|---|---|---|
| its / it's | it's = it is | It's late; the fund cut its fees. |
| affect / effect | affect = verb, effect = noun (usually) | Rates affect stocks; the effect was big. |
| fewer / less | fewer = countable, less = uncountable | fewer breaks, less risk |
| then / than | then = time, than = comparison | Check, then send. Better than before. |
| principal / principle | principal = main/loan amount; principle = rule | repay principal; a core principle |
| who / whom | who = subject (he), whom = object (him) | Whom did you email? (you emailed him) |
Key idea
Quick test for its/it's: say "it is". If it fits, use it's.Next: Practice