When
/wɛn/noun
At what time; at the time that.
Did you know?English when is a direct descendant of a Proto-Indo-European interrogative stem meaning “which/what,” so even time itself was once asked like a riddle.
Etymological Timeline
Proto-Indo-European
PIE
*kʷo- / *kʷi-
“Interrogative stem meaning “who? what? which?””
Proto-Germanic
PGmc
*hwan
“An interrogative/adverbial form meaning “when” or “at what time””
Old English
OE
hwænne
“When; at what time; whenever”
Middle English
ME
whan / when
“When; at the time that”
Modern English
English
when
“At what time; at the time that”