From Middle English who, hwo, huo, wha, hwoa, hwa, from Old English hwā (dative hwām, genitive hwæs), from Proto-Germanic *hwaz, from Proto-Indo-European *kʷos, *kʷis. Spelling change hw > wh in Middle English (without sound change in initial consonant cluster), while sound change /hw/ > /h/ due to wh-cluster reduction after a bizarre instance of three consecutive vowel shifts of /aː/ to /ɔː/ to /oː/ in Middle English and further to /uː/ in Early Modern English (although only the shift from /ɔː/ to /oː/ is unusual). Compare how, which underwent this change earlier (in Old English), and thus is spelt h.
Compare Scots wha, West Frisian wa, Dutch wie, Low German we, German wer, Danish hvem, Norwegian Bokmål hvem, Norwegian Nynorsk kven, Icelandic hver.
who (singular or plural, nominative case, objective whom, who, possessive whose)
- (interrogative) What person or people; which person or people; asks for the identity of someone. (used in a direct or indirect question)
- (interrogative) What is one's position; asks whether someone deserves to say or do something.
- (relative) The person or people that.
- (relative, archaic) Whoever, he who, they who.
who (plural whos)
- A person under discussion; a question of which person.