The word(s) "why" appears 48 time(s) in 45 verse(s) in Quran in Muhammad Pickthal translation.

(21) When he said unto his father: O my father! why worshippest thou that which heareth not nor seeth, nor can in aught avail thee?

(22) why did not the believers, men and women, when ye heard it, think good of their own own folk, and say: It is a manifest untruth?

(23) why did they not produce four witnesses? Since they produce not witnesses, they verily are liars in the sight of Allah.

(24) And they say: What aileth this messenger (of Allah) that he eateth food and walketh in the markets? why is not an angel sent down unto him, to be a warner with him.

(25) Or (why is not) treasure thrown down unto him, or why hath he not a paradise from whence to eat? And the evil-doers say: Ye are but following a man bewitched.

(26) And those who look not for a meeting with Us say: why are angels not sent down unto us and (why) do we not see our Lord! Assuredly they think too highly of themselves and are scornful with great pride.

(27) And those who disbelieve say: why is the Qur'an not revealed unto him all at once? (It is revealed) thus that We may strengthen thy heart therewith; and We have arranged it in right order.

(28) He said: O my people! why will ye hasten on the evil rather than the good? why will ye not ask pardon of Allah, that ye may receive mercy.

(29) Otherwise, if disaster should afflict them because of that which their own hands have sent before (them), they might say: Our Lord! why sentest Thou no messenger unto us, that we might have followed Thy revelations and been of the believers?

(30) But when there came unto them the Truth from Our presence, they said: why is he not given the like of what was given unto Moses? Did they not disbelieve in that which was given unto Moses of old? They say: Two magics that support each other; and they say: Lo! in both we are disbelievers.