The word(s) "warn" appears 147 time(s) in 131 verse(s) in Quran in Muhammad Pickthal translation.

(61) And We sent not unto any township a warner, but its pampered ones declared: Lo! we are disbelievers in that wherewith ye have been sent.

(62) And We have given them no scriptures which they study, nor sent We unto them, before thee, any warner.

(63) Say (unto them, O Muhammad): I exhort you unto one thing only: that ye awake, for Allah's sake, by twos and singly, and then reflect: There is no madness in your comrade. He is naught else than a warner unto you in face of a terrific doom.

(64) And no burdened soul can bear another's burden, and if one heavy laden crieth for (help with) his load, naught of it will be lifted even though he (unto whom he crieth) be of kin. Thou warnest only those who fear their Lord in secret, and have established worship. He who groweth (in goodness), groweth only for himself, (he cannot by his merit redeem others). Unto Allah is the journeying.

(65) Thou art but a warner.

(66) Lo! We have sent thee with the Truth, a bearer of glad tidings and a warner; and there is not a nation but a warner hath passed among them.

(67) And they cry for help there, (saying): Our Lord! Release us; we will do right, not (the wrong) that we used to do. Did not We grant you a life long enough for him who reflected to reflect therein? And the warner came unto you. Now taste (the flavour of your deeds), for evil-doers have no helper.

(68) And they swore by Allah, their most binding oath, that if a warner came unto them they would be more tractable than any of the nations; yet, when a warner came unto them it aroused in them naught save repugnance,

(69) That thou mayst warn a folk whose fathers were not warned, so they are heedless.

(70) Whether thou warn them or thou warn them not, it is alike for them, for they believe not.