The word(s) "when" appears 1006 time(s) in 918 verse(s) in Quran in Muhammad Pickthal translation.

(91) O People of the Scripture! Why will ye argue about Abraham, when the Torah and the Gospel were not revealed till after him? Have ye then no sense?

(92) O People of the Scripture! Why disbelieve ye in the revelations of Allah, when ye (yourselves) bear witness (to their truth)?

(93) And lo! there is a party of them who distort the Scripture with their tongues, that ye may think that what they say is from the Scripture, when it is not from the Scripture. And they say: It is from Allah, when it is not from Allah; and they speak a lie concerning Allah knowingly.

(94) when Allah made (His) covenant with the prophets, (He said): Behold that which I have given you of the Scripture and knowledge. And afterward there will come unto you a messenger, confirming that which ye possess. Ye shall believe in him and ye shall help him. He said: Do ye agree, and will ye take up My burden (which I lay upon you) in this (matter)? They answered: We agree. He said: Then bear ye witness. I will be a witness with you.

(95) Seek they other than the religion of Allah, when unto Him submitteth whosoever is in the heavens and the earth, willingly or unwillingly, and unto Him they will be returned.

(96) Say: O People of the Scripture! Why disbelieve ye in the revelations of Allah, when Allah (Himself) is Witness of what ye do?

(97) Say: O People of the Scripture! Why drive ye back believers from the way of Allah, seeking to make it crooked, when ye are witnesses (to Allah's guidance)? Allah is not unaware of what ye do.

(98) How can ye disbelieve, when it is ye unto whom Allah's revelations are recited, and His messenger is in your midst? He who holdeth fast to Allah, he indeed is guided unto a right path.

(99) On the Day when (some) faces will be whitened and (some) faces will be blackened; and as for those whose faces have been blackened, it will be said unto them: Disbelieved ye after your (profession of) belief? Then taste the punishment for that ye disbelieved.

(100) Lo! ye are those who love them though they love you not, and ye believe in all the Scripture. when they fall in with you they say: We believe; but when they go apart they bite their finger-tips at you, for rage. Say: Perish in your rage! Lo! Allah is Aware of what is hidden in (your) breasts.