The word(s) "certainly" appears 476 time(s) in 417 verse(s) in Quran in Muhammad Habib Shakir translation.

(41) And were it not for Allah's grace upon you and His mercy a party of them had certainly designed to bring you to perdition and they do not bring (aught) to perdition but their own souls, and they shall not harm you in any way, and Allah has revealed to you the Book and the wisdom, and He has taught you what you did not know, and Allah's grace on you is very great.

(42) Allah has cursed him; and he said: Most certainly I will take of Thy servants an appointed portion:

(43) And most certainly I will lead them astray and excite in them vain desires, and bid them so that they shall slit the ears of the cattle, and most certainly I will bid them so that they shall alter Allah's creation; and whoever takes the Shaitan for a guardian rather than Allah he indeed shall suffer a manifest loss.

(44) And whatever is in the heavens and whatever is in the earth is Allah's and certainly We enjoined those who were given the Book before you and (We enjoin) you too that you should be careful of (your duty to) Allah; and if you disbelieve, then surely whatever is in the heavens and whatever is in the earth is Allah's and Allah is Self-sufficient, Praise-worthy.

(45) And there is not one of the followers of the Book but most certainly believes in this before his death, and on the day of resurrection he (Isa) shall be a witness against them.

(46) And certainly Allah made a covenant with the children of Israel, and We raised up among them twelve chieftains; and Allah said: Surely I am with you; if you keep up prayer and pay the poor-rate and believe in My apostles and assist them and offer to Allah a goodly gift, I will most certainly cover your evil deeds, and I will most certainly cause you to enter into gardens beneath which rivers flow, but whoever disbelieves from among you after that, he indeed shall lose the right way.

(47) certainly they disbelieve who say: Surely, Allah-- He is the Messiah, son of Marium. Say: Who then could control anything as against Allah when He wished to destroy the Messiah son of Marium and his mother and all those on the earth? And Allah's is the kingdom of the heavens and the earth and what is between them; He creates what He pleases; and Allah has power over all things,

(48) And relate to them the story of the two sons of Adam with truth when they both offered an offering, but it was accepted from one of them and was not accepted from the other. He said: I will most certainly slay you. (The other) said: Allah only accepts from those who guard (against evil).

(49) For this reason did We prescribe to the children of Israel that whoever slays a soul, unless it be for manslaughter or for mischief in the land, it is as though he slew all men; and whoever keeps it alive, it is as though he kept alive all men; and certainly Our apostles came to them with clear arguments, but even after that many of them certainly act extravagantly in the land.

(50) And you will see many of them striving with one another to hasten in sin and exceeding the limits, and their eating of what is unlawfully acquired; certainly evil is that which they do.