~てやる (casual/condescending benefactive)
grammar35 sentences
The casual benefactive auxiliary ~てやる, meaning 'to do X for someone (below oneself or equal)' — typically directed at equals or those of lower status. Can sound condescending, blunt, or determined. More rough/casual than ~てあげる. 教えてやる ('I'll teach you' — implying it's a favor or imposition). Part of the giving/receiving verb system.