The word(s) "warner" appears 58 time(s) in 54 verse(s) in Quran in Mohsin Khan translation.

(21) And never did We destroy a township but it had its warners

(22) And that I should recite the Qur'an, then whosoever receives guidance, receives it for the good of his ownself; and whosoever goes astray, say (to him): "I am only one of the warners."

(23) And you (O Muhammad صلى الله عليه وسلم) were not at the side of the Tur (Mount) when We did call: [it is said that Allah called the followers of Muhammad صلى الله عليه وسلم, and they answered His Call, or that Allah called Musa (Moses)]. But (you are sent) as a mercy from your Lord, to give warning to a people to whom no warner had come before you: in order that they may remember or receive admonition. [Tafsir At-Tabari].

(24) And they say: "Why are not signs sent down to him from his Lord? Say: "The signs are only with Allah, and I am only a plain warner."

(25) Or say they: "He (Muhammad صلى الله عليه وسلم) has fabricated it?" Nay, it is the truth from your Lord, so that you may warn a people to whom no warner has come before you (O Muhammad صلى الله عليه وسلم): in order that they may be guided.

(26) O Prophet (Muhammad صلى الله عليه وسلم)! Verily, We have sent you as witness, and a bearer of glad tidings, and a warner,

(27) And We have not sent you (O Muhammad صلى الله عليه وسلم) except as a giver of glad tidings and a warner to all mankind, but most of men know not.

(28) And We did not send a warner to a township but those who were given the worldly wealth and luxuries among them said: "We believe not in the (Message) with which you have been sent."

(29) And We had not given them Scriptures which they could study, nor sent to them before you (O Muhammad صلى الله عليه وسلم) any warner (Messenger).

(30) Say (to them O Muhammad صلى الله عليه وسلم): "I exhort you to one (thing) only: that you stand up for Allah's sake in pairs and singly, and reflect (within yourselves the life history of the Prophet صلى الله عليه وسلم): there is no madness in your companion (Muhammad صلى الله عليه وسلم). He is only a warner to you in face of a severe torment."