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

(91) And indeed Yusuf (Joseph) did come to you, in times gone by, with clear signs, but you ceased not to doubt in that which he did bring to you: till when he died you said: "No Messenger will Allah send after him." Thus Allah leaves astray him who is a Musrif (a polytheist, an oppressor, a criminal, sinner who commit great sins) and a Murtab (one who doubts Allah's warning and His Oneness).

(92) Giving glad tidings [of Paradise to the one who believes in the Oneness of Allah (i.e. Islamic Monotheism) and fears Allah much (abstains from all kinds of sins and evil deeds) and loves Allah much (performing all kinds of good deeds which He has ordained)], and warning (of punishment in the Hell-Fire to the one who disbelieves in the Oneness of Allah), but most of them turn away, so they hear not.

(93) But if they turn away, then say (O Muhammad صلى الله عليه وسلم): "I have warned you of a Sa'iqah (a destructive awful cry, torment, hit, a thunderbolt) like the Sa'iqah which overtook 'Ad and Thamud (people)."

(94) And thus We have revealed to you (O Muhammad صلى الله عليه و سلم) a Qur'an in Arabic that you may warn the Mother of the Towns (Makkah) and all around it, and warn (them) of the Day of Assembling of which there is no doubt: when a party will be in Paradise (those who believed in Allah and followed what Allah's Messenger صلى الله عليه و سلم brought them) and a party in the blazing Fire (Hell) (those who disbelieved in Allah and followed not what Allah's Messenger صلى الله عليه و سلم brought them).

(95) Shall We then (warn you not and) take away the Reminder (this Qur'an) from you, because you are a people Musrifun.

(96) And similarly, We sent not a warner before you (O Muhammad صلى الله عليه و سلم) to any town (people) but the luxurious ones among them said: "We found our fathers following a certain way and religion, and we will indeed follow their footsteps."

(97) (The warner) said: "Even if I bring you better guidance than that which you found your fathers following?" They said: "Verily, we disbelieve in that with which you have been sent."

(98) We sent it (this Qur'an) down on a blessed night [(i.e. night of Al-Qadr, Surah No. 97) in the month of Ramadan - the 9th month of the Islamic calendar]. Verily, We are ever warning [mankind that Our Torment will reach those who disbelieve in Our Oneness of Lordship and in Our Oneness of worship].

(99) We created not the heavens and the earth and all that is between them except with truth, and for an appointed term. But those who disbelieve turn away from that whereof they are warned.

(100) Say (O Muhammad صلى الله عليه وسلم): "I am not a new thing among the Messengers (of Allah i.e. I am not the first Messenger) nor do I know what will be done with me or with you. I only follow that which is revealed to me, and I am but a plain warner."