Slay

'To slay' is an irregular verb. Its forms are given here:

Base form	past tense	-ed participle	Remarks
slay	slew	slain

This is one of the "the 250 or so irregular verbs" listed in Quirk 1985. The list "contains most of the irregular verbs in present-day English ... but is not meant to be exhaustive, particularly with regard to derivative verbs." AWE has copied most of the entries in that list. The verb 'to slay' belongs to Quirk's Class 4 B h.

'To slay' is rarely used in British English, where it is considered archaic - it does appear in the Authorised Version and derivative texts. It is used more often in American English, particularly in journalism, where it is a cliché of description of murders and homicides (it may be speculated that this is not least because slew takes up less space in a headline than killed). In British academic English, say kill.