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

(21) Say: "Verily, my Lord hath guided me to a way that is straight,- a religion of right,- the path (trod) by Abraham the true in Faith, and he (certainly) joined not gods with Allah."

(22) They said: "Our Lord! We have wronged our own souls: If thou forgive us not and bestow not upon us Thy Mercy, we shall certainly be lost."

(23) The men on the heights will call to certain men whom they will know from their marks, saying: "Of what profit to you were your hoards and your arrogant ways?

(24) For We had certainly sent unto them a Book, based on knowledge, which We explained in detail,- a guide and a mercy to all who believe.

(25) The leaders, the arrogant party among his people, said: "O Shu'aib! we shall certainly drive thee out of our city - (thee) and those who believe with thee; or else ye (thou and they) shall have to return to our ways and religion." He said: "What! even though we do detest (them)?

(26) Remember ye were on the hither side of the valley, and they on the farther side, and the caravan on lower ground than ye. Even if ye had made a mutual appointment to meet, ye would certainly have failed in the appointment: But (thus ye met), that Allah might accomplish a matter already enacted; that those who died might die after a clear Sign (had been given), and those who lived might live after a Clear Sign (had been given). And verily Allah is He Who heareth and knoweth (all things).

(27) If there had been immediate gain (in sight), and the journey easy, they would (all) without doubt have followed thee, but the distance was long, (and weighed) on them. They would indeed swear by Allah, "If we only could, we should certainly have come out with you": They would destroy their own souls; for Allah doth know that they are certainly lying.

(28) If they had intended to come out, they would certainly have made some preparation therefor; but Allah was averse to their being sent forth; so He made them lag behind, and they were told, "Sit ye among those who sit (inactive)."

(29) certain of the desert Arabs round about you are hypocrites, as well as (desert Arabs) among the Medina folk: they are obstinate in hypocrisy: thou knowest them not: We know them: twice shall We punish them: and in addition shall they be sent to a grievous penalty.

(30) And there are those who put up a mosque by way of mischief and infidelity - to disunite the Believers - and in preparation for one who warred against Allah and His Messenger aforetime. They will indeed swear that their intention is nothing but good; But Allah doth declare that they are certainly liars.