why
AHD:[hwº, wº]
D.J.[hwai, wai]
K.K.[hwa!, wa!]
adv.（副词）
For what purpose, reason, or cause; with what intention, justification, or motive:
为什么：为什么目的、原因或起源；以什么目标、借口或动机：
Why is the door shut? Why do birds sing?
门为什么关了?鸟为什么唱歌?
conj.（连接词）
The reason, cause, or purpose for which:
为…的原因、起因或目的：
I know why you left.
我知道你离开的原因
Usage Problem On account of which; for which:
【用法疑难】 因为，为什么：
“The reason why [regular verbs] are called regular is that we can predict what all the other three forms are” (Randolph Quirk)
“[规则动词] 之所以称为规则是因为我们能够预知动词另三种形式的变化” (伦道夫·夸克)
n.（名词）
【复数】 whys
The cause or intention underlying a given action or situation:
原因，动机：在一特点行为或情况下隐藏的起因或目的：
studying the whys of antisocial behavior.
研究反社会行为的原因
A difficult problem or question.
难题，令人费解的问题
interj.（感叹词）
Used to express mild surprise, indignation, or impatience.
用于表示轻微的吃惊、生气或不耐烦
【用法】
Many critics have held that why is redundant in the expression the reason why, as in The reason why he accepted the nomination is not clear. It is true that why could be eliminated from such examples with no loss to the sense, but the construction has been used by reputable English writers since the Renaissance.See Usage Note at where
许多批评家认为在the reason why 这种表达中， why 是多余的， 如在句子The reason why he accepted the nomination is mot clear.（他接受提名的原因不太明确。） why 可以从这种例子中除去，对句子意义并不影响， 但是自从文艺复兴以来这种结构已为颇有名望的英语作家的广泛应用参见 where
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