"why" can be compared to an old Latin form qui, an ablative form, meaning how. Today "why" is used as a question word to ask the reason or purpose of something.
8 1) Please tell me why is it like that. [grammatically incorrect unless the punctuation is changed. Please tell me: Why is it like that? The question: "Why is [etc.]" is a question form in English: Why is the sky blue? Why is it that children require so much attention? Why is it [or some thing] like that?
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 sentence, and it has to do primarily with relevance. Grammarians often use the terms "restrictive" and "non-restrictive" when it comes to relative clauses.
Good explanation of why it's optional in this case, although I'm not convinced that reason is the only reasonable antecedent of why. For example, the explanation why is a common usage, and I don't think you can freely substitute that in that case either. (Perhaps it's already a contraction of the explanation of why?)
As to why I do, I really don't know. (=...but if you want to ask why I do, I don't know.) I am going for sure. As to whether Jane will go along too, you will have to ask her yourself. English is fun, as to math, forget it. (contrast) John and Mary fought over small things all the time, things that you and I most likely won't give a damn.
Since we can say "Why can we grow taller?", "Why cannot we grow taller?" is a logical and properly written negative. We don't say "Why we can grow taller?" so the construct should not be "Why we cannot grow taller?" The reason is that auxiliaries should come before the subject to make an interrogative.
Possible Duplicate: Why should the first person pronoun 'I' always be capitalized? I realize that at one time a lot of nouns in English were capitalized, but I can't understand the pattern of those left. Is there a reason why I still capitalized while you and me are not? Could it have something to do with hand writing rather than the printed page?
It’s a headline, first of all, where some grammatical rules are different anyway. So this is not a sentence, but a noun phrase: (This section tells you) why to use page-level permissions. That is, it tells you why you should use them. “Why to…” and “why not to…” are very common in headings to encourage or discourage the reader, respectively. The heading could just as well be ...
