The word(s) "certain" appears 498 time(s) in 437 verse(s) in Quran in Muhammad Habib Shakir translation.

(251) And certainly We made above you seven heavens; and never are We heedless of creation.

(252) And certainly We sent Nuh to his people, and he said: O my people! serve Allah, you have no god other than Him; will you not then guard (against evil)?

(253) And the chiefs of those who disbelieved from among his people said: He is nothing but a mortal like yourselves who desires that he may have superiority over you, and if Allah had pleased, He could certainly have sent down angels. We have not heard of this among our fathers of yore:

(254) He said: In a little while they will most certainly be repenting.

(255) And certainly We gave Musa the Book that they may follow a right direction.

(256) certainly we are promised this, and (so were) our fathers aforetime; this is naught but stories of those of old.

(257) Never did Allah take to Himself a son, and never was there with him any (other) god-- in that case would each god have certainly taken away what he created, and some of them would certainly have overpowered others; glory be to Allah above what they describe!

(258) And were it not for Allah's grace upon you and His mercy in this world and the hereafter, a grievous chastisement would certainly have touched you on account of the discourse which you entered into.

(259) And certainly We have sent to you clear communications and a description of those who have passed away before you, and an admonition to those who guard (against evil).

(260) certainly We have revealed clear communications, and Allah guides whom He pleases to the right way.