whatvswhenWhich spelling fits?

Quick tell: what is a intj, when is an adverb, so they fill different roles in a sentence.

Which to use

“what” is an intj and “when” is an adverb - they look or sound alike but fill different roles in a sentence.

#6,911
“what” frequency rank
#10,973
“when” frequency rank
17884
confusion score

Side-by-Side Comparison

Feature what when
Definition Quoi ? Comment ? Quand.

Where the eye mixes what and when

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

4 ch
what
4 ch
when

Visual trap between what and when

These two trip readers on the page rather than in the ear: what is \wat\ while when is \ˈwɛn\. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (intj vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 17884, derived from the frequency rank of both members and their visual similarity.

what is recorded at frequency rank #6,911, classified as anintj, pronounced \wat\. when is at rank #10,973, tagged as anadv, pronounced \ˈwɛn\.

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 17884, this pair ranks #380,987 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of what vs when

Shared letters: hw. Private to "what": at. Private to "when": en.

"what" · 4 letters · shape CCVC  ·  "when" · 4 letters · shape CCVC

Known mistypes of this pair

  • whathwat · waht · whatt · whhat · whta · wwhat
  • whenhwen · wehn · whenn · whhen · whne · wwhen

Frequently Asked Questions

Can "what" and "when" be used interchangeably?
No - they are not even the same part of speech. "what" is an intj and "when" an adverb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "what" or "when"?
"what" is the more common of the two: it sits at frequency rank #6,911 in our French list, against #10,973 for "when". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "what" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "when" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #380,987 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "what" and "when" also get mixed up with nearby pairs, the highest-scored neighbour is "when vs wren". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #380,987 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list