Between, betwixt, among, amongst, amid, amidst are all prepositions and their meanings are quite similar, that’s why students of English are often confused about their use.
Between and among are the most widely used, as the others are more formal (amid) or even archaic, that is, they are no longer used by speakers, and can only be found in written or literary texts. That's the case of betwixt, which is the same as between.
We say that something is between two things if the things are on either side of it: I was sitting between my mother and my father. (Note that the root of this word, “tw”, is related to number two). Between is also used when there are more than two things but each one is clearly distinct from the others: Luxemburg lies between Belgium, France and Germany.
However, we say that something is among (or amongst) a group of things when these things cannot be told apart, that is, a collection of things we do not see separately:
They used to live in a little hut among the trees.
She grabbed the title among a total of 20 competitors.
I saw him walking among the crowd.
If something is among a group of similar things, it is one of these things. In this case, it means “included in”: Among the collection of pictures there is one by Picasso.
Amid or amidst is very formal and is mainly used with ideas and abstract nouns:
The politician finished his speech amid tremendous applause.
The law was approved amid a great deal of controversy.
It can also mean “surrounded by”: The house was in a beautiful position amid vineyards.
Idioms:
To be sandwiched between... is to be so close to two people or things that there is not enough space to move. My poor little car was sandwiched between a Rolls Royce and a Mercedes.
To read between the lines is to discover a meaning in something that is not openly stated: He is not going to say what he really feels, but you can read between the lines and guess that he isn’t happy with the situation.
Between you and me, or between ourselves are used to mean that something is or should be kept a secret. Now between ourselves, for this is strictly confidential, I'm quite alarmed at the prospect.
If you are between the devil and the deep blue sea, you must choose between two unpleasant situations. We seemed to be between the devil and the deep blue sea: it didn’t matter which way we went.
To come between two people is to disrupt their relationship. You have a nice example in Sade’s song “Nothing can come between us”.
Now you can check what you have learned by doing this exercise: