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

(11) They (also) said: "Allah took our promise not to believe in an messenger unless He showed us a sacrifice consumed by Fire (From heaven)." Say: "There came to you messengers before me, with clear Signs and even with what ye ask for: why then did ye slay them, if ye speak the truth?"

(12) And why should ye not fight in the cause of Allah and of those who, being weak, are ill-treated (and oppressed)?- Men, women, and children, whose cry is: "Our Lord! Rescue us from this town, whose people are oppressors; and raise for us from thee one who will protect; and raise for us from thee one who will help!"

(13) Hast thou not turned Thy vision to those who were told to hold back their hands (from fight) but establish regular prayers and spend in regular charity? When (at length) the order for fighting was issued to them, behold! a section of them feared men as - or even more than - they should have feared Allah: They said: "Our Lord! why hast Thou ordered us to fight? Wouldst Thou not Grant us respite to our (natural) term, near (enough)?" Say: "Short is the enjoyment of this world: the Hereafter is the best for those who do right: Never will ye be dealt with unjustly in the very least!

(14) why should ye be divided into two parties about the Hypocrites? Allah hath upset them for their (evil) deeds. Would ye guide those whom Allah hath thrown out of the Way? For those whom Allah hath thrown out of the Way, never shalt thou find the Way.

(15) (Both) the Jews and the Christians say: "We are sons of Allah, and his beloved." Say: "why then doth He punish you for your sins? Nay, ye are but men,- of the men he hath created: He forgiveth whom He pleaseth, and He punisheth whom He pleaseth: and to Allah belongeth the dominion of the heavens and the earth, and all that is between: and unto Him is the final goal (of all)"

(16) But why do they come to thee for decision, when they have (their own) law before them?- therein is the (plain) command of Allah; yet even after that, they would turn away. For they are not (really) People of Faith.

(17) why do not the rabbis and the doctors of Law forbid them from their (habit of) uttering sinful words and eating things forbidden? Evil indeed are their works.

(18) why turn they not to Allah, and seek His forgiveness? For Allah is Oft-forgiving, Most Merciful.

(19) They say: "why is not an angel sent down to him?" If we did send down an angel, the matter would be settled at once, and no respite would be granted them.

(20) They say: "why is not a sign sent down to him from his Lord?" Say: "Allah hath certainly power to send down a sign: but most of them understand not.