Why here is an interjection, placed at the beginning of a sentence to express surprise:Is it nine o'clock already?Why, i must have fallen asleep!Are you suggesting he stole the money?I don't know why, but it seems to me that bob would sound a bit strange if he said, why is it that you have to get going? in that situation.Thus we say:You never know, which is why but you never know.
The Power of ‘Why’ in Safety - EHS Daily Advisor
The Power of ‘Why’ in Safety - EHS Daily Advisor

The Power of ‘Why’ in Safety - EHS Daily Advisor of Why Everyone's Obsessed With Imogen Lucie's Latest Instagram Post. .

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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, …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 …