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

(381) But when they reached the junction of the two seas, they forgot their fish, and it took its way through the sea as in a tunnel.

(382) So when they had passed further on (beyond that fixed place), Musa (Moses) said to his boy-servant: "Bring us our morning meal; truly, we have suffered much fatigue in this, our journey."

(383) He said: "Do you remember when we betook ourselves to the rock? I indeed forgot the fish; none but Shaitan (Satan) made me forget to remember it. It took its course into the sea in a strange (way)!"

(384) So they both proceeded, till, when they embarked the ship, he (Khidr) scuttled it. Musa (Moses) said: "Have you scuttled it in order to drown its people? Verily, you have committed a thing "Imr" (a Munkar - evil, bad, dreadful thing)."

(385) Then they both proceeded, till, when they came to the people of a town, they asked them for food, but they refused to entertain them. Then they found therein a wall about to collapse and he (Khidr) set it up straight. [Musa (Moses)] said: If you had wished, surely, you could have taken wages for it!"

(386) Until, when he reached the setting place of the sun, he found it setting in a spring of black muddy (or hot) water. And he found near it a people. We (Allah) said (by inspiration): "O Dhul-Qarnain! Either you punish them, or treat them with kindness."

(387) Until, when he came to the rising place of the sun, he found it rising on a people for whom We (Allah) had provided no shelter against the sun.

(388) Until, when he reached between two mountains, he found, before (near) them (those two mountains), a people who scarcely understood a word.

(389) "Give me pieces (blocks) of iron;" then, when he had filled up the gap between the two mountain-cliffs, he said: "Blow;" then when he had made them (red as) fire, he said: "Bring me molten copper to pour over them."

(390) (Dhul-Qarnain) said: "This is a mercy from my Lord, but when the Promise of my Lord comes, He shall level it down to the ground. And the Promise of my Lord is ever true."