each和every的不同

下面有段解释，说得非常清楚：

Each and every are both determiners used with singular nouns to indicate quantity. Each indicates two or more objects or people and every indicates three or more. Each can also be used as a pronoun, but every cannot be. Study the following:

each ~ both

She had clearly been in a fight. She had bruises on each leg and cuts on each arm (OR: on both legs / on both arms, BUT NOT: on every leg / on every arm)
My parents have moved to the capital. Each of them works in a bank. (OR They both work? / They each work? BUT NOT: Every one of them works?
We each had a suitcase and each one weighed over 30 kilos. ( = two people, two suitcases)
He was holding a revolver in each hand / in both hands
( = two hands, two revolvers)
He was holding a revolver with both hands ( = two hands, one revolver)

两者都有“每个”的意思，但用法不同：
（1）each具有名词和形容词的功能，every只有形容词的功能。
（2）each指两个或两个以上的人或事物中的“每个”；every是指三个以上的人或事物的“全体”，和all