The word(s) "vain" appears 29 time(s) in 29 verse(s) in Quran in Muhammad Pickthal translation.

(11) And when they had cast, Moses said: That which ye have brought is magic. Lo! Allah will make it vain. Lo! Allah upholdeth not the work of mischief-makers.

(12) Those are they for whom is naught in the Hereafter save the Fire. (All) that they contrive here is vain and (all) that they are wont to do is fruitless.

(13) Those are they who disbelieve in the revelations of their Lord and in the meeting with Him. Therefor their works are vain, and on the Day of Resurrection We assign no weight to them.

(14) And who shun vain conversation,

(15) Build ye on every high place a monument for vain delight?

(16) When they came upon you from above you and from below you, and when eyes grew wild and hearts reached to the throats, and ye were imagining vain thoughts concerning Allah.

(17) And We created not the heaven and the earth and all that is between them in vain. That is the opinion of those who disbelieve. And woe unto those who disbelieve, from the Fire!

(18) They say: Came not your messengers unto you with clear proofs? They say: Yea, verily. They say: Then do ye pray, although the prayer of disbelievers is in vain.

(19) Those who disbelieve and turn (men) from the way of Allah, He rendereth their actions vain.

(20) Now when ye meet in battle those who disbelieve, then it is smiting of the necks until, when ye have routed them, then making fast of bonds; and afterward either grace or ransom till the war lay down its burdens. That (is the ordinance). And if Allah willed He could have punished them (without you) but (thus it is ordained) that He may try some of you by means of others. And those who are slain in the way of Allah, He rendereth not their actions vain.