The word(s) "doubt" appears 83 time(s) in 78 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) This is the Book; in it is guidance sure, without doubt, to those who fear Allah;

(2) And if ye are in doubt as to what We have revealed from time to time to Our servant, then produce a Sura like thereunto; and call your witnesses or helpers (If there are any) besides Allah, if your (doubts) are true.

(3) Would ye question your Messenger as Moses was questioned of old? but whoever changeth from Faith to Unbelief, Hath strayed without doubt from the even way.

(4) The Truth is from thy Lord; so be not at all in doubt.

(5) O ye who believe! When ye deal with each other, in transactions involving future obligations in a fixed period of time, reduce them to writing Let a scribe write down faithfully as between the parties: let not the scribe refuse to write: as Allah Has taught him, so let him write. Let him who incurs the liability dictate, but let him fear His Lord Allah, and not diminish aught of what he owes. If they party liable is mentally deficient, or weak, or unable Himself to dictate, Let his guardian dictate faithfully, and get two witnesses, out of your own men, and if there are not two men, then a man and two women, such as ye choose, for witnesses, so that if one of them errs, the other can remind her. The witnesses should not refuse when they are called on (For evidence). Disdain not to reduce to writing (your contract) for a future period, whether it be small or big: it is juster in the sight of Allah, More suitable as evidence, and more convenient to prevent doubts among yourselves but if it be a transaction which ye carry out on the spot among yourselves, there is no blame on you if ye reduce it not to writing. But take witness whenever ye make a commercial contract; and let neither scribe nor witness suffer harm. If ye do (such harm), it would be wickedness in you. And fear Allah. And Allah teaches you. And Allah is well acquainted with all things.

(6) "Our Lord! Thou art He that will gather mankind Together against a day about which there is no doubt; for Allah never fails in His promise."

(7) But how (will they fare) when we gather them together against a day about which there is no doubt, and each soul will be paid out just what it has earned, without (favour or) injustice?

(8) The Truth (comes) from Allah alone; so be not of those who doubt.

(9) Without doubt, among men, the nearest of kin to Abraham, are those who follow him, as are also this Prophet and those who believe: And Allah is the Protector of those who have faith.

(10) Allah! There is no god but He: of a surety He will gather you together against the Day of Judgment, about which there is no doubt. And whose word can be truer than Allah's?