when

Etymology

It is inherited from Middle English whanne, later when,^[2][3][4] inherited from Old English hwænne, also hwenne and hwonne,^[4][3][5] from Proto-Germanic *hwan (“at what time, when”).^[4][6] It is cognate with Old Saxon hwan, Old Frisian hwenne (“until, if”), Middle Dutch wan (surviving in Dutch wanneer), Old High German hwanne, whose modern German descendants are wann (“when”) and wenn (“if, whenever”), and Gothic 𐍈𐌰𐌽 (ƕan, “when, how”).^[3][7][4] The OED explains it as a derivative, with a nasal element of uncertain origin, of the interrogative stem of who,^[7] which goes back to Proto-Indo-European *kʷo- (“stem of relative and interrogative pronouns”);^[4][8] then and than were formed in the same way from the demonstrative stem of the and that.^[5] Outside Germanic the OED compares Latin quom, cum (“when”), Old Irish cuin (“when”) and Welsh pan (“when”),^[7] and Ayto points to Latin quandō (“when”), the source of quandary, built on the same base with a dental suffix.^[9]

Earliest recorded meaning

Barnhart's first record of the Old English word is from before 899, in Alfred's translation of Bede's Ecclesiastical History.^[3] The OED's earliest quotations, from the West Saxon Gospels, use it in direct and indirect questions: at what time?, on what occasion?^[7] Etymonline instead finds the conjunction "at the time that" first, in late Old English, and dates the interrogative use to the early 13th century.^[4]

Semantic evolution

From late Old English the word was also a relative after a noun of time, "at or on which", as in the day when.^[7] An indefinite sense "at some time", with when and when for "now and then", was used until 1543,^[7] and survives only in compounds such as somewhen, elsewhen and anywhen.^[7] From about 1350 it could follow a preposition, as in since when and till when,^[7] and Merriam-Webster dates this pronoun use to the 14th century.^[10] A non-temporal sense, "in which case", appears in the early 15th century,^[4] and the conjunction also came to express a contrast, "although", or a reason, "considering that".^[11] Johnson (1755) gave "at the time that" as the first sense.^[12] The noun, the time of an event, is recorded from 1616,^[10] and say when, said when pouring someone a drink, from 1889.^[4] North American colloquial speech has used I knew her when, meaning in the past, since the mid 20th century.^[13]

Timeline

• before 899 – Old English, at what time; in Alfred's translation of Bede.^[3][7]
• late Old English – conjunction, at the time that; relative after a noun of time.^[4][7]
• c. 1200 – Middle English whanne, in the Ormulum.^[3]
• c. 1320 – the spelling when, in whensoever.^[3]
• c. 1350 – after a preposition: since when, till when.^[7]
• early 15th century – non-temporal use, in which case.^[4]
• 1616 – noun, the time of an event.^[10]
• 1889 – say when.^[4]

Meanings

Adverb

1. At what time; on what occasion: When does the train leave?^[11][10][7]
2. In indirect questions, the time at which: Ask her when the shop opens.^[11][7]
3. At or during which (time): the winter when the river froze.^[11][10][7]

Conjunction

1. At the time that; as soon as; after: Call me when you arrive.^[11][10]
2. Although; whereas: He took the bus when he could have walked.^[11]
3. Considering that: How can she win when she never practises?^[11]

Pronoun

1. What or which time, after a preposition: Since when has he lived here?^[10][7]

Noun

1. The time of an event: the when and the where of the meeting.^[10][11]

Phrases

1. say when: tell me when to stop, said when pouring a drink.^[11][4]

Related words

• who
• what
• whence
• then
• than
• quandary
• whenever

Usage notes

Collins advises against using when for in which after a noun that does not denote time, as in a definition of a condition.^[11]

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
3. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b c d e f g h i j k l Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
6. ^ Orel, Vladimir (2003), A Handbook of Germanic Etymology, Leiden / Boston: Brill
7. ^ a b c d e f g h i j k l m n o Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
8. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
9. ^ Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
10. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
11. ^ a b c d e f g h i j Collins English Dictionary (2023), Glasgow: HarperCollins
12. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
13. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press