The word(s) "unless" appears 35 time(s) in 35 verse(s) in Quran in Abdullah Yusuf Ali translation.

(31) unless he repents, believes, and works righteous deeds, for Allah will change the evil of such persons into good, and Allah is Oft-Forgiving, Most Merciful,

(32) "I will certainly punish him with a severe penalty, or execute him, unless he bring me a clear reason (for absence)."

(33) And dispute ye not with the People of the Book, except with means better (than mere disputation), unless it be with those of them who inflict wrong (and injury): but say, "We believe in the revelation which has come down to us and in that which came down to you; Our Allah and your Allah is one; and it is to Him we bow (in Islam)."

(34) There is for you an excellent example (to follow) in Abraham and those with him, when they said to their people: "We are clear of you and of whatever ye worship besides Allah: we have rejected you, and there has arisen, between us and you, enmity and hatred for ever,- unless ye believe in Allah and Him alone": But not when Abraham said to his father: "I will pray for forgiveness for thee, though I have no power (to get) aught on thy behalf from Allah." (They prayed): "Our Lord! in Thee do we trust, and to Thee do we turn in repentance: to Thee is (our) Final Goal.

(35) "unless I proclaim what I receive from Allah and His Messages: for any that disobey Allah and His Messenger,- for them is Hell: they shall dwell therein for ever."