As a conjunction:
* quand (most common): This is the most general translation for "when" as a conjunction, meaning "at the time that".
* Example: "I will call you when I get home." → "Je t'appellerai quand j'arriverai à la maison."
* lorsque (more formal): This is a more formal equivalent of "quand".
* Example: "When I saw her, I was surprised." → "Lorsque je l'ai vue, j'ai été surpris."
* dès que: This translates to "as soon as".
* Example: "I will leave when you are ready." → "Je partirai dès que tu seras prêt."
As an adverb:
* quand: This can also translate "when" as an adverb, meaning "at what time".
* Example: "When did you arrive?" → "Quand es-tu arrivé?"
As an interrogative pronoun:
* quand: This translates "when" as an interrogative pronoun, asking for the time of something.
* Example: "When will you be back?" → "Quand reviendras-tu?"
It's important to consider the context to choose the most appropriate translation.