The word(s) "could" appears 96 time(s) in 90 verse(s) in Quran in Mohsin Khan translation.

(1) Their likeness is as the likeness of one who kindled a fire; then, when it lighted all around him, Allah took away their light and left them in darkness. (So) they could not see.

(2) The lightning almost snatches away their sight, whenever it flashes for them, they walk therein, and when darkness covers them, they stand still. And if Allah willed, He could have taken away their hearing and their sight. Certainly, Allah has power over all things.

(3) And verily, you will find them (the Jews) the greediest of mankind for life and (even greedier) than those who ascribe partners to Allah (and do not believe in Resurrection - Majus, pagans, and idolaters). Everyone of them wishes that he could be given a life of a thousand years. But the grant of such life will not save him even a little from (due) punishment. And Allah is All-Seer of what they do.

(4) They followed what the Shayatin (devils) gave out (falsely of the magic) in the lifetime of Sulaiman (Solomon). Sulaiman did not disbelieve, but the Shayatin (devils) disbelieved, teaching men magic and such things that came down at Babylon to the two angels, Harut and Marut, but neither of these two (angels) taught anyone (such things) till they had said, "We are only for trial, so disbelieve not (by learning this magic from us)." And from these (angels) people learn that by which they cause separation between man and his wife, but they could not thus harm anyone except by Allah's Leave. And they learn that which harms them and profits them not. And indeed they knew that the buyers of it (magic) would have no share in the Hereafter. And how bad indeed was that for which they sold their ownselves, if they but knew.

(5) Many of the people of the Scripture (Jews and Christians) wish that if they could turn you away as disbelievers after you have believed, out of envy from their ownselves, even after the truth (that Muhammad صلى الله عليه وسلم is Allah's Messenger) has become manifest unto them. But forgive and overlook, till Allah brings His Command. Verily, Allah is Able to do all things.

(6) And of mankind are some who take (for worship) others besides Allah as rivals (to Allah). They love them as they love Allah. But those who believe, love Allah more (than anything else). If only, those who do wrong could see, when they will see the torment, that all power belongs to Allah and that Allah is Severe in punishment.

(7) In (to) this worldly life and in the Hereafter. And they ask you concerning orphans. Say: "The best thing is to work honestly in their property, and if you mix your affairs with theirs, then they are your brothers. And Allah knows him who means mischief (e.g. to swallow their property) from him who means good (e.g. to save their property). And if Allah had wished, He could have put you into difficulties. Truly, Allah is All-Mighty, All-Wise."

(8) And how could you take it (back) while you have gone in unto each other, and they have taken from you a firm and strong covenant?

(9) And even if We had sent down unto you (O Muhammad صلى الله عليه وسلم) a Message written on paper so that they could touch it with their hands, the disbelievers would have said: "This is nothing but obvious magic!"

(10) If you could but see when they will be held over the (Hell) Fire! They will say: "Would that we were but sent back (to the world)! Then we would not deny the Ayat (proofs, evidence, verses, lessons, revelations, etc.) of our Lord, and we would be of the believers!"