"I am among you."
Translation:Je suis parmi vous.
"Je suis entre vous" = "I am between you" (physically between two people).
"Je suis parmi vous" = "I am among you" (physically among several people, always more than two).
I can't think of any physical situation in which we would use among in English but entre in French. But when talking about abstract things, this might happen, so what you have seen on Duo is probably similar to:
- "Le secret entre les femmes" = "The secret between/among the women" (figuratively between two/several people).
N.B. I'm not a native speaker in either language.
"Entre is used when there is question of two: between his hands, between his arms, between him and me.
"Parmi is used with a collection of objects and always demands after it a plural noun or a collective noun: among men, in the world ...
"Parmi always requires a plural or collective nouns.
"There are cases where one can use either entre or parmi when the complement is a plural.."
Indeed! The Tips and Hints section specifically says, "if the larger group is uniform in some specific way, entre can also mean 'among'," and yet Duolingo will not accept "entre" in this instance. That aside, "parmi" would be the more usual translation for "among" (but it should still accept "entre" or else revise its explanation).
If you interpret that explanation as "the larger group" meaning "the whole group including the thing that is discussed", then it makes perfectly sense. Otherwise I would say it is wrong. So for example:
- "Nous sommes entre femmes" = "We are among women" if all of us present here are women, no men around. --> The whole group is uniform.
- "Nous sommes entre des femmes" = "We are between women" if we are for example men but there are two women, one on each side of us. --> Only the surrounding group is uniform.