I like how English has a system of wh- questions and th- answers. Where? There. What? That. When? Then. Wherefore? Therefore.
But there are a few missing words. There's no tho to go with who, no thy to go with why, no thich to go with which.
@dog I don't think "thou" is really related to "who" though, especially because it's not always a valid answer. I /think/ (though I'm not entirely certain, this was a while ago that I read it) that what/that and where/there at least are etymologically related
@Austin_Dern That doesn't really work though because the th- form of such groupings seems to be the more distal one (e.g. there is further away than here), but "thou" is closer than "he".
@yatchi I have Learned A Thing today!
@yatchi *fanfare*
@Felthry Who? Thou. Older English. Discarded and replaced with you.