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

(31) We verily have displayed (Our warnings) in this Qur'an that they may take heed, but it increaseth them in naught save aversion.

(32) Naught hindereth Us from sending portents save that the folk of old denied them. And We gave Thamud the she-camel - a clear portent save to warn.

(33) And (it was a warning) when we told thee: Lo! thy Lord encompasseth mankind, and We appointed the sight which We showed thee as an ordeal for mankind, and (likewise) the Accursed Tree in the Qur'an. We warn them, but it increaseth them in naught save gross impiety.

(34) With truth have We sent it down, and with truth hath it descended. And We have sent thee as naught else save a bearer of good tidings and a warner.

(35) (But hath made it) straight, to give warning of stern punishment from Him, and to bring unto the believers who do good works the news that theirs will be a fair reward,

(36) And to warn those who say: Allah hath chosen a son,

(37) We send not the messengers save as bearers of good news and warners. Those who disbelieve contend with falsehood in order to refute the Truth thereby. And they take Our revelations and that wherewith they are threatened as a jest.

(38) And warn them of the Day of anguish when the case hath been decided. Now they are in a state of carelessness, and they believe not.

(39) And We make (this Scripture) easy in thy tongue, (O Muhammad) only that thou mayst bear good tidings therewith unto those who ward off (evil), and warn therewith the froward folk.

(40) Say (O Muhammad, unto mankind): I warn you only by the Inspiration. But the deaf hear not the call when they are warned.