The word(s) "nay" appears 143 time(s) in 137 verse(s) in Quran in Mohsin Khan translation.

(41) We hasten unto them with good things. nay, [it is a Fitnah (trial) in this worldly life so that they will have no share of good things in the Hereafter] but they perceive not. [Tafsir Al-Qurtubi].

(42) nay, but their hearts are covered from (understanding) this (the Qur'an), and they have other (evil) deeds, besides, which they are doing.

(43) Or say they: There is madness in him? nay, but he brought them the truth [i.e. Tauhid: Worshipping Allah Alone in all aspects, the Qur'an and the religion of Islam], but most of them (the disbelievers) are averse to the truth.

(44) And if the truth had been in accordance with their desires, verily, the heavens and the earth, and whosoever is therein would have been corrupted! nay, We have brought them their reminder, but they turn away from their reminder.

(45) nay, but they say the like of what the men of old said.

(46) nay, but We have brought them the truth (Islamic Monotheism), and verily, they (disbelievers) are liars.

(47) Verily those who brought forth the slander (against 'Aishah رضي الله عنها the wife of the Prophet صلى الله عليه وسلم) are a group among you. Consider it not a bad thing for you. nay, it is good for you. Unto every man among them will be paid that which he had earned of the sin, and as for him among them who had the greater share therein, his will be a great torment.

(48) Is there a disease in their hearts? Or do they doubt or fear lest Allah and His Messenger (صلى الله عليه وسلم) should wrong them in judgement. nay, it is they themselves who are the Zalimun (polytheists, hypocrites and wrong-doers).

(49) nay, they deny the Hour (the Day of Resurrection), and for those who deny the Hour, We have prepared a flaming Fire (i.e. Hell).

(50) And indeed they have passed by the town [of Prophet Lut (Lot)] on which was rained the evil rain. Did they (disbelievers) not then see it (with their own eyes)? nay! But they used not to expect any resurrection.