adverb / noun
why
WHY/waɪ/
For what reason something happens or is done.
The child asks why the plate broke, pointing to the fallen ball.

Etymology
Old English hwi was an instrumental case form of hwæt, “what.” It asked “by what means?” or “for what purpose?”, connecting why directly with questions about the reason or purpose behind something.
In context
Why are we not questioning this?
So why is that a good example?
More examples
- Tell me why you left.
- She explained the why behind her decision.
- I wonder why the train stopped.
Forms
why · whys