Why no, no more then reason Why is used here as an interjection The oed doesn't explain why it is used in that manner
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First it was just a question expressing doubt reduced to its.
You never know, which 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. For why (also hyphenated or written as one word) meaning why as a direct interrogative was used in old and middle english (see the med's entry), but it became obsolete. Why do people use the latter terminology
For one thing, i find it confusing It doesn't help that bce is similar to bc But moreover, there is only one letter of difference between the two terms,. That's a very good question

I've used all of the other ones on.
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

