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

(21) Say: Behold what is in the heavens and the earth! But revelations and warnings avail not folk who will not believe.

(22) (Saying): Serve none but Allah. Lo! I am unto you from Him a warner and a bringer of good tidings.

(23) A likely thing, that thou wouldst forsake aught of that which hath been revealed unto thee, and that thy breast should be straitened for it, because they say: Why hath not a treasure been sent down for him, or an angel come with him? Thou art but a warner, and Allah is in charge of all things.

(24) And We sent Noah unto his folk (and he said): Lo! I am a plain warner unto you.

(25) If only there had been among the generations before you men possessing a remnant (of good sense) to warn (their people) from corruption in the earth, as did a few of those whom We saved from them! The wrong-doers followed that by which they were made sapless, and were guilty.

(26) Those who disbelieve say: If only some portent were sent down upon him from his Lord! Thou art a warner only, and for every folk a guide.

(27) And warn mankind of a day when the doom will come upon them, and those who did wrong will say: Our Lord! Reprieve us for a little while. We will obey Thy call and will follow the messengers. (It will be answered): Did ye not swear before that there would be no end for you?

(28) This is a clear message for mankind in order that they may be warned thereby, and that they may know that He is only One Allah, and that men of understanding may take heed.

(29) And say: Lo! I, even I, am a plain warner,

(30) He sendeth down the angels with the Spirit of His command unto whom He will of His bondmen, (saying): warn mankind that there is no Allah save Me, so keep your duty unto Me.