"When will he come?"
かれ - he/him は - the particle indicating かれ as the subject of the sentence いつ - when (can be placed in a few different places in the sentence, but right before the verb is common) きます - will come (a form of the verb きる) か - indicating that the sentence is a question
Hope this helps! I don't know how fine gained you were looking for.
Cultural sidenote: あなた, かのじょ and かれ are often omitted, use someone's name or あの人(あのひと) instead!
- あなた sounds rude to keep using it more than needed; I think it's kind of like pointing at the person every time you say it, which is a tad off putting.
- かのじょ and かれ usually mean "girlfriend" and "boyfriend" respectively, using them to simply mean she/he is also a tad off putting; I think people would usually assume you'd ask when their boyfriend will come when you say this!
- It's very common in Japanese to use someone's name while you're talking in their face, so feel free to do it! (not in English though, people will be like "Why are you asking what games Fonzie likes? I'm Fonzie!")
- あの=that over there / 人(ひと)=person. "When does that person work?" / "When does she work?" when you don't know her name, again this is normal in Japanese. (again not in English, "that person" sounds a tad rude to use out of the blue, in my experience)