Which to use
“affect” is a verb and “effect” is a noun - they look or sound alike but fill different roles in a sentence.
- #2,510
- “affect” frequency rank
- #1,015
- “effect” frequency rank
- 99
- confusion score
“Affect” is almost always the verb — to affect something is to influence it. “Effect” is almost always the noun — an effect is the result. (Each has a rarer flip side: “effect” can be a verb meaning to bring about, and “affect” a noun in psychology.)
Side-by-Side Comparison
| Feature | affect | effect |
|---|---|---|
| Definition | To influence or alter. | The result or outcome of a cause. |
Where the spellings diverge
Shared letters are muted; the letters that actually set affect and effect apart are highlighted. They share 5 letters in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
affect and effect form a confusable pair in the English index, two distinct headwords that are easily confused because they look alike, sound alike, or both. They differ by a single letter - a in “affect” becomes e in “effect” - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 99, derived from the frequency rank of both members and their visual similarity.
affect is recorded at frequency rank #2,510, classified as averb, pronounced /əˈfɛkt/. effect is at rank #1,015, tagged as anoun, pronounced /ɪˈfɛkt/.
Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.
Frequency comparison
Frequently Asked Questions
What is the difference between "affect" and "effect"?
Can "affect" and "effect" be used interchangeably?
Remembering affect vs effect
The fastest way to pick the right one every time.
- Check the role first: if you need a verb, it's “affect”; for a noun, it's “effect”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “affect” entry
- Browse more pairs most likely to be confused. Most confusable