The word(s) "why" appears 77 time(s) in 72 verse(s) in Quran in Abdullah Yusuf Ali translation.

(41) They say: "why does he not bring us a sign from his Lord?" Has not a Clear Sign come to them of all that was in the former Books of revelation?

(42) why did not the believers - men and women - when ye heard of the affair,- put the best construction on it in their own minds and say, "This (charge) is an obvious lie"?

(43) why did they not bring four witnesses to prove it? When they have not brought the witnesses, such men, in the sight of Allah, (stand forth) themselves as liars!

(44) And why did ye not, when ye heard it, say? - "It is not right of us to speak of this: Glory to Allah! this is a most serious slander!"

(45) And they say: "What sort of a messenger is this, who eats food, and walks through the streets? why has not an angel been sent down to him to give admonition with him?

(46) "Or (why) has not a treasure been bestowed on him, or why has he (not) a garden for enjoyment?" The wicked say: "Ye follow none other than a man bewitched."

(47) Such as fear not the meeting with Us (for Judgment) say: "why are not the angels sent down to us, or (why) do we not see our Lord?" Indeed they have an arrogant conceit of themselves, and mighty is the insolence of their impiety!

(48) Those who reject Faith say: "why is not the Qur'an revealed to him all at once? Thus (is it revealed), that We may strengthen thy heart thereby, and We have rehearsed it to thee in slow, well-arranged stages, gradually.

(49) And he took a muster of the Birds; and he said: "why is it I see not the Hoopoe? Or is he among the absentees?

(50) He said: "O my people! why ask ye to hasten on the evil in preference to the good? If only ye ask Allah for forgiveness, ye may hope to receive mercy.