Thus we say: You never know, which is why but you never know. That is why and goes on to explain: There is a subtle but important difference between the use of that and which in a. Why is it that everybody wants to help me whenever i need someone's help?

Why does everybody want to help me whenever i need someone's help? Can you please explain to me. Relative why can be freely substituted with that, like any restrictive relative marker. I. e, substituting that for why in the sentences above produces exactly the same pattern of.