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.
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?
"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.
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?)
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.
Why the bank usage was adopted by newspapers is another question. One can only say the bank usage has become the general way of writing amount of money and currency contrary to the way we speak.
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?
I know it originates from "head shrinking", but it doesn't help me a lot to understand the etymology. Why are psychiatrists called that? Is it like "my head is swollen [from anguish, misery, stress...
There is no recorded reason why Doe, except there was, and is, a range of others like Roe. So it may have been a set of names that all rhymed and that law students could remember. Or it could be that they were formed from a mnemonic, like the english pronouciation of a prayer or scripture in Latin/Greek.