As a conjunction:
* quand (most common): This is used to introduce a subordinate clause that indicates time.
* Example: "When I go to the store, I'll buy some milk." > "Quand j'irai au magasin, j'achèterai du lait."
* lorsque: This is a more formal version of "quand" and is often used in written French.
* Example: "When I was a child, I loved to play outside." > "Lorsque j'étais enfant, j'adorais jouer dehors."
* à l'instant où: This is used to emphasize the precise moment something happens.
* Example: "When the phone rang, I answered it." > "À l'instant où le téléphone a sonné, j'ai répondu."
As an adverb:
* quand: This is used to ask about time.
* Example: "When did you arrive?" > "Quand êtes-vous arrivé?"
* à quel moment: This is a more formal version of "quand" used to ask about time.
* Example: "When will the meeting be held?" > "À quel moment aura lieu la réunion?"
As part of a phrase:
* à partir de quand: This means "from when".
* Example: "When does the movie start?" > "À partir de quand le film commence-t-il?"
* jusqu'à quand: This means "until when".
* Example: "When are you staying here?" > "Jusqu'à quand restez-vous ici?"
The best way to choose the correct translation of "when" is to consider the context of the sentence.