The word(s) "warn" appears 150 time(s) in 135 verse(s) in Quran in Mohsin Khan translation.

(61) 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."

(62) 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].

(63) Then We saved him and those with him in the ship, and made it (the ship) an Ayah (a lesson, a warning) for the 'Alamin (mankind, jinn and all that exists).

(64) And indeed We have left thereof an evident Ayah (a lesson and a warning and a sign - the place where the Dead Sea is now in Palestine) for a folk who understand.

(65) 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."

(66) So that they become ingrate for that which We have given them, and that they take their enjoyment (as a warning and a threat), but they will come to know.

(67) 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.

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

(69) 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.

(70) 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."