The word(s) "certain" appears 144 time(s) in 135 verse(s) in Quran in Abdullah Yusuf Ali translation.

(31) "Enough is Allah for a witness between us and you: we certainly knew nothing of your worship of us!"

(32) But none believed in Moses except some children of his people, because of the fear of Pharaoh and his chiefs, lest they should persecute them; and certainly Pharaoh was mighty on the earth and one who transgressed all bounds.

(33) "'Nor call on any, other than Allah;- Such will neither profit thee nor hurt thee: if thou dost, behold! thou shalt certainly be of those who do wrong.'"

(34) They said: "O Shu'aib! much of what thou sayest we do not understand! In fact among us we see that thou hast no strength! Were it not for thy family, we should certainly have stoned thee! for thou hast among us no great position!"

(35) We certainly gave the Book to Moses, but differences arose therein: had it not been that a word had gone forth before from thy Lord, the matter would have been decided between them, but they are in suspicious doubt concerning it.

(36) She said: "There before you is the man about whom ye did blame me! I did seek to seduce him from his (true) self but he did firmly save himself guiltless!.... and now, if he doth not my bidding, he shall certainly be cast into prison, and (what is more) be of the company of the vilest!"

(37) So the king said: "Bring ye him unto me." But when the messenger came to him, (Joseph) said: "Go thou back to thy lord, and ask him, 'What is the state of mind of the ladies who cut their hands'? For my Lord is certainly well aware of their snare."

(38) "Nor do I absolve my own self (of blame): the (human) soul is certainly prone to evil, unless my Lord do bestow His Mercy: but surely my Lord is Oft-forgiving, Most Merciful."

(39) They said: "We shall certainly seek to get our wish about him from his father: Indeed we shall do it."

(40) They said: "By Allah! indeed has Allah preferred thee above us, and we certainly have been guilty of sin!"