"sobald" is easy: "as soon as", e.g. "Ich rufe Dich an, sobald ich zu Hause bin" = I'll call you as soon as/when I get home. (Of course you'd have to keep in mind that in English, you have several other possibilities, like "right after" or "immediately when/after") "wenn" vs. "als": Use "als" only when talking about the past: "Als ich das Haus betrat, brannten alle Kerzen" = When I entered the house, all the candles were burning. In all other cases use "wenn" for "when". Exception: "whenever", "every time", "always": "Immer wenn ich meine Großmutter besuchte, gab es Haferbrei zum Frühstück" = Whenever/Every time I visited my grandmother, there was porridge for breakfast. (Again, you have more possibilities in English, e.g. "used to" or "would" for past habits, all of which will usually translate as "immer wenn" or "wenn") Hope this helps!