The word(s) "warn" appears 127 time(s) in 113 verse(s) in Quran in Muhammad Habib Shakir translation.

(1) Surely those who disbelieve, it being alike to them whether you warn them, or do not warn them, will not believe.

(2) Surely We have sent you with the truth as a bearer of good news and as a warner, and you shall not be called upon to answer for the companions of the flaming fire.

(3) (All) people are a single nation; so Allah raised prophets as bearers of good news and as warners, and He revealed with them the Book with truth, that it might judge between people in that in which they differed; and none but the very people who were given it differed about it after clear arguments had come to them, revolting among themselves; so Allah has guided by His will those who believe to the truth about which they differed and Allah guides whom He pleases to the right path.

(4) (We sent) apostles as the givers of good news and as warners, so that people should not have a plea against Allah after the (coming of) apostles; and Allah is Mighty, Wise.

(5) O followers of the Book! indeed Our Apostle has come to you explaining to you after a cessation of the (mission of the) apostles, lest you say: There came not to us a giver of good news or a warner, so indeed there has come to you a giver of good news and a warner; and Allah has power over all things.

(6) Say: What thing is the weightiest in testimony? Say: Allah is witness between you and me; and this Quran has been revealed to me that with it I may warn you and whomsoever it reaches. Do you really bear witness that there are other gods with Allah? Say: I do not bear witness. Say: He is only one Allah, and surely I am clear of that which you set up (with Him).

(7) And We send not apostles but as announcers of good news and givers of warning, then whoever believes and acts aright, they shall have no fear, nor shall they grieve.

(8) And warn with it those who fear that they shall be gathered to their Lord-- there is no guardian for them, nor any intercessor besides Him-- that they may guard (against evil).

(9) And this is a Book We have revealed, blessed, verifying that which is before it, and that you may warn the metropolis and those around her; and those who believe in the hereafter believe in it, and they attend to their prayers constantly.

(10) O assembly of jinn and men! did there not come to you apostles from among you, relating to you My communications and warning you of the meeting of this day of yours? They shall say: We bear witness against ourselves; and this world's life deceived them, and they shall bear witness against their own souls that they were unbelievers.