* When (as a question word): "Quand"
* When (as a conjunction): "Quand"
* When (as a relative pronoun): "Lorsque" or "Quand"
Here are some examples:
* When will you come? -> Quand viendras-tu?
* I will call you when I get home. -> Je t'appellerai quand je serai rentré(e).
* The time when we met. -> Le moment où nous nous sommes rencontrés.
Let me know if you have a specific sentence in mind and I can help you find the best translation!