This is the 6912th most frequent Chinese word.
為什麼
"為什麼" means "why."
The word '為什麼' is used here to ask for a reason or justification, in the form of a direct question.
為什麼我應該幫助你？
Why should I help you?
In this sentence, '為什麼' seeks the cause for someone's action or non-action.
他為什麼沒來上課？
Why did he not come to class?
Here, '為什麼' introduces a subordinate clause providing the reasoning behind a choice.