* ἐν (en): This is the most common preposition meaning "in," "within," "among," or "at." It's used for location, time, and sometimes means "by means of." Example: ἐν τῇ πόλει (en tē polei) - in the city.
* εἰς (eis): This preposition means "into," "toward," or "onto." It implies movement *into* a place. Example: εἰς τὴν πόλιν (eis tēn polin) - into the city.
* ἀμφί (ampi): This means "around," "about," or "concerning," and can sometimes be translated as "in" when referring to something surrounding something else.
Therefore, to give you the best answer, I need more context. What is the sentence or phrase you're trying to translate?