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

(51) Or do they say: He has forged it? Nay! it is the truth from your Lord that you may warn a people to whom no warner has come before you, that they may follow the right direction.

(52) O Prophet! surely We have sent you as a witness, and as a bearer of good news and as a warner,

(53) And We have not sent you but to all the men as a bearer of good news and as a warner, but most men do not know.

(54) And We never sent a warner to a town but those who led lives in ease in it said: We are surely disbelievers in what you are sent with.

(55) And We have not given them any books which they read, nor did We send to them before you a warner.

(56) Say: I exhort you only to one thing, that rise up for Allah's sake in twos and singly, then ponder: there is no madness in your fellow-citizen; he is only a warner to you before a severe chastisement.

(57) And a burdened soul cannot bear the burden of another and if one weighed down by burden should cry for (another to carry) its burden, not aught of it shall be carried, even though he be near of kin. You warn only those who fear their Lord in secret and keep up prayer; and whoever purifies himself, he purifies himself only for (the good of) his own soul; and to Allah is the eventual coming.

(58) You are naught but a warner.

(59) Surely We have sent you with the truth as a bearer of good news and a warner; and there is not a people but a warner has gone among them.

(60) And they shall cry therein for succour: O our Lord! take us out, we will do good deeds other than those which we used to do. Did We not preserve you alive long enough, so that he who would be mindful in it should mind? And there came to you the warner; therefore taste; because for the unjust, there is no helper.