We use between to refer to two things which are clearly separated. We use among to talk about things which are not clearly separated because they are part of a group or crowd or mass of objects

between uses when you talk about only two.... but among uses when you talk about more than two

Among means being surrounded by or within something. Among also means being part of a group. For example, "Nikeline was among the first people to finish the race" (You were part of a group of people to win a race). "There were caterpillars among the leaves" (The caterpillars were surrounded by leaves) Between is more for expressing separation. "There was a bike between the cars" "They were such best friends nothing could come between them." To show the difference BETWEEN the two words: Among the 10 people in the room, 4 wanted to stay home, 4 wanted to go to the party, and 2 were in between. (2 people did not know if they wanted to stay home or if they wanted to go to the party). I hope this helps a little. Sometimes it's tough to explain when you've grown up speaking English.

https://www.italki.com/question/348102 Please refer to Su.Ki's answer here. She explained it better than I ever could. It is not quite as simple as 'between' is for two things and 'among' is for three or more.

The question should be "When should I use between versus among?" Between can mean in the middle two points such as .I. the I is between 2 periods(dots), or Uruguay is between Brazil and Argentina. It can also a close personal connection, for example, let's keep this secret between you and me(that means don't tell anyone else). Among usually means there is a group and you're some where in the middle, but not exactly in the middle .....I..............I... There are 2 I's among many/the dots. It can also mean a personal connection as well. Don't worry you can tell us you are among friends.(That means there are friends around and we won't tell anybody what you tell us.) If you have any other questions just let me know.