The word(s) "when" appears 916 time(s) in 828 verse(s) in Quran in Mohsin Khan translation.

(341) And when those who associated partners with Allah see their (Allah's so-called) partners, they will say: "Our Lord! These are our partners whom we used to invoke besides you." But they will throw back their word at them (and say): "Surely! You indeed are liars!"

(342) And (remember) the Day when We shall raise up from every nation a witness against them from amongst themselves. And We shall bring you (O Muhammad صلى الله عليه و سلم) as a witness against these. And We have sent down to you the Book (the Qur'an) as an exposition of everything, a guidance, a mercy, and glad tidings for those who have submitted themselves (to Allah as Muslims).

(343) And fulfil the Covenant of Allah (Bai'ah: pledge for Islam) when you have covenanted, and break not the oaths after you have confirmed them - and indeed you have appointed Allah your surety. Verily! Allah knows what you do.

(344) So when you want to recite the Qur'an, seek refuge with Allah from Shaitan (Satan), the outcast (the cursed one).

(345) And when We change a Verse (of the Qur'an,) in place of another - and Allah knows best what He sends down - they (the disbelievers) say: "You (O Muhammad صلى الله عليه و سلم) are but a Muftari! (forger, liar)." Nay, but most of them know not.

(346) (Remember) the Day when every person will come up pleading for himself, and every one will be paid in full for what he did (good or evil, belief or disbelief in the life of this world) and they will not be dealt with unjustly.

(347) So, when the promise came for the first of the two, We sent against you slaves of Ours given to terrible warfare. They entered the very innermost parts of your homes. And it was a promise (completely) fulfilled.

(348) (And We said): "If you do good, you do good for your ownselves, and if you do evil (you do it) against yourselves." Then, when the second promise came to pass, (We permitted your enemies) to disgrace your faces and to enter the mosque (of Jerusalem) as they had entered it before, and to destroy with utter destruction all that fell in their hands.

(349) And when We decide to destroy a town (population), We (first) send a definite order (to obey Allah and be righteous) to those among them [or We (first) increase in number those of its population] who lead a life of luxury. Then, they transgress therein, and thus the word (of torment) is justified against it (them). Then We destroy it with complete destruction.

(350) And lower unto them the wing of submission and humility through mercy, and say: "My Lord! Bestow on them Your Mercy as they did bring me up when I was young."