For location:
* dans: This is the most common translation and can be used for both physical locations and abstract spaces. For example, "in the house" would be "dans la maison" and "in the future" would be "dans le futur."
* à: Used for locations that are more specific or precise, often with a verb of motion. For example, "in Paris" would be "à Paris."
* sur: Used for locations that are on a surface. For example, "in the car" would be "dans la voiture" but "in the back seat" would be "sur la banquette arrière."
For time:
* en: Used for a period of time. For example, "in five minutes" would be "en cinq minutes" and "in the morning" would be "en matinée."
* dans: Used for a future time. For example, "in a week" would be "dans une semaine."
Other contexts:
* en: Used for some expressions such as "in fact" ("en fait") and "in short" ("en bref").
* à: Used for some expressions such as "in vain" ("en vain") and "in response" ("en réponse").
It's important to consider the context of the sentence to determine the best translation.
Please provide me with an example sentence, and I can help you choose the most accurate translation of "in".