When should I use among, and when should I use between?
Between you and me, we are among the many inquisitive people who wonder about this on a regular basis. Most people have learned the rule that between is used with two entities and among with three or more; however, that is not always the case. On closer examination, it becomes clear that in certain cases between is called for with three or more entities.
Frances Peck tells us in her article Usage Myths that "among suggests a general sort of sharing and works well when the relationship is general":
a discussion among the members
you are among friends
choosing among many cheeses
The author also says that "when three or more entities relate to each other individually and equally rather than collectively, or when the relationship is not general but reciprocal," between is the correct choice. For example,
A free trade agreement between (notamong) Canada, Mexico, and the United States …
A contract between (notamong) five interested parties …
A partnership between (notamong) the federal, provincial and territorial governments …
Also, you should opt for between in the following situations:
when designating a one-to-one relationship even when no number is specified:
Offering assistance as a symbol of co-operation between nations…
when only one item is involved, suggesting repetition:
The poet paused between each and every verse to take a deep breath.
before a series of singular nouns or pronouns:
Between horseback riding, fencing and studying, Bridget doesn't have any time for Joe.
Between you, me and the lamppost, Jack will find it difficult to adapt to his new surroundings.
after the noun difference:
What is the difference between the Ottawa 67s and the Ottawa Senators?
There are cultural differences between Americans and Canadians.
with the verbs divide and share:
The award money was divided between Jack, Bridget and Joe.
However, before a plural noun or pronoun, either between or among may be used:
Jack, Bridget and Joe shared the award between (or among) all their friends.
They should share the award between (or among) them.
I hope that this helps you out. In closing, I would like you to consider these quirky idioms that appear to defy logic: