Which to use
“what” is a determiner and “why” is an adverb - they look or sound alike but fill different roles in a sentence.
- #46
- “what” frequency rank
- #125
- “why” frequency rank
- 171
- confusion score
Side-by-Side Comparison
| Feature | what | why |
|---|---|---|
| Definition | Which, especially which of an open-ended set of possibilities. | For what cause, reason, or purpose. |
Where the spellings diverge
Shared letters are muted; the letters that actually set what and why apart are highlighted. They share 2 letters in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
what and why 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 1 letter(s) in length - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 171, derived from the frequency rank of both members and their visual similarity.
what is recorded at frequency rank #46, classified as adet, pronounced /wɒt/. why is at rank #125, tagged as anadv, pronounced /wæ/.
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.
With a confusion score of 171, this pair ranks #529,773 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Frequency comparison
Frequently Asked Questions
Can "what" and "why" be used interchangeably?
Remembering what vs why
The fastest way to pick the right one every time.
- Check the role first: if you need a determiner, it's “what”; for an adverb, it's “why”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “what” entry
- Browse more pairs most likely to be confused. Most confusable