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

(81) This is Allah's guidance, He guides thereby whom He pleases of His servants; and if they had set up others (with Him), certainly what they did would have become ineffectual for them.

(82) And certainly you have come to Us alone as We created you at first, and you have left behind your backs the things which We gave you, and We do not see with you your intercessors about whom you asserted that they were (Allah's) associates in respect to you; certainly the ties between you are now cut off and what you asserted is gone from you.

(83) And they swear by Allah with the strongest of their oaths, that if a sign came to them they would most certainly believe in it. Say: Signs are only with Allah; and what should make you know that when it comes they will not believe?

(84) Say: Then Allah's is the conclusive argument; so if He please, He would certainly guide you all.

(85) Or lest you should say: If the Book had been revealed to us, we would certainly have been better guided than they, so indeed there has come to you clear proof from your Lord, and guidance and mercy. Who then is more unjust than he who rejects Allah's communications and turns away from them? We will reward those who turn away from Our communications with an evil chastisement because they turned away.

(86) Most certainly then We will question those to whom (the apostles) were sent, and most certainly We will also question the apostles;

(87) Then most certainly We will relate to them with knowledge, and We were not absent.

(88) And certainly We have established you in the earth and made in it means of livelihood for you; little it is that you give thanks.

(89) And certainly We created you, then We fashioned you, then We said to the angels: Prostrate to Adam. So they did prostrate except Iblis; he was not of those who prostrated.

(90) He said: As Thou hast caused me to remain disappointed I will certainly lie in wait for them in Thy straight path.