whenvswhen'sWhat's the difference?

Quick tell: when is a adverb, when's is a contraction, so they fill different roles in a sentence.

Which to use

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

#48
“when” frequency rank
#22,550
“when's” frequency rank
22598
confusion score

Side-by-Side Comparison

Feature when when's
Definition At what time? At which time? Upon which occasion or circumstance? Used to introduce direct or indirect questions about time. Contraction of when + is.

Where the spellings diverge

Shared letters are muted; the letters that actually set when and when's apart are highlighted. They share 4 letters in sequence, which is exactly why the eye skips the difference.

4 ch
when
6 ch
when's

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: when is /ˈwɛn/ while when's is /wɛnz/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “when” sits inside “when's”, and the parts of speech differ too (adverb vs contraction), which is usually the fastest check. Our composite confusion score for this pair is 22598, derived from the frequency rank of both members and their visual similarity.

when is recorded at frequency rank #48, classified as anadv, pronounced /ˈwɛn/. when's is at rank #22,550, tagged as acontraction, pronounced /wɛnz/.

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 22598, this pair ranks #415,408 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of when vs when's

Shared letters: ehnw. Private to "when": -. Private to "when's": s.

"when" · 4 letters · shape CCVC  ·  "when's" · 5 letters · shape CCVCC

Known mistypes of this pair

  • whenhwen · wehn · whenn · whhen · whne · wwhen

Frequency comparison

when#48
when's#22,550

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "when" and "when's" be used interchangeably?
No - they are not even the same part of speech. "when" is an adverb and "when's" a contraction, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "when" or "when's"?
"when" is the more common of the two: it sits at frequency rank #48 in our English list, against #22,550 for "when's". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Remembering when vs when's

The fastest way to pick the right one every time.

  • Check the role first: if you need an adverb, it's “when”; for a contraction, it's “when's”.
  • See each word in full, definition, IPA, etymology and its other confusables. Full “when” entry
  • Browse more pairs most likely to be confused. Most confusable

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

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list