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

(381) And if those who disbelieve fight with you, they would certainly turn (their) backs, then they would not find any protector or a helper.

(382) certainly Allah had shown to His Apostle the vision with truth: you shall most certainly enter the Sacred Mosque, if Allah pleases, in security, (some) having their heads shaved and (others) having their hair cut, you shall not fear, but He knows what you do not know, so He brought about a near victory before that.

(383) And if they wait patiently until you come out to them, it would certainly be better for them, and Allah is Forgiving, Merciful.

(384) And certainly We created man, and We know what his mind suggests to him, and We are nearer to him than his life-vein.

(385) certainly you were heedless of it, but now We have removed from you your veil, so your sight today is sharp.

(386) And certainly We created the heavens and the earth and what is between them in six periods and there touched Us not any fatigue.

(387) Or did they create the heavens and the earth? Nay! they have no certainty.

(388) And certainly he saw him in another descent,

(389) certainly he saw of the greatest signs of his Lord.

(390) They are naught but names which you have named, you and your fathers; Allah has not sent for them any authority. They follow naught but conjecture and the low desires which (their) souls incline to; and certainly the guidance has come to them from their Lord.