both用于描述两人或两物.可以用both boys,both the boys或both of the boys,表示“两个男孩都……”的意思....the assassination of both Kennedy brothers.……暗杀肯尼迪兄弟俩.Both the kings under whom he served had financial difficaulties.他效劳的两位国王都有财政困难.Both of the diplomas blushed when the company thanked them.当公司向他们致谢时,两位外交官都脸红了.也可以说people or things both do something,把both放在谓语动词之前表示“两人或两物都……”的意义.Tony and Nigel both laughed noisily.托尼和内基尔两人都哈哈大笑起来.every指某集体的全部成员而不仅仅是其中的几个成员.注意：every意味着这个集体必须包括两个以上的成员.every只能与单数名词连用.He listened to every news bulletin on the radio.他收听电台广播的每一条简明新闻.Every house had to be cleaned.必须打扫每一幢房子.We are still so far from granting an equal chance to every child.我们现在还远远做不到让每一个孩子得到同样的机会.each用于谈及某集体中每一人或物.当说话人把某集体的成员看成各个个体时,用each,不用every.注意：each 可用于两人或两物,指一对中的每个成员.each只能与单数名词连用.The treatment is different in each case.每种情况的处理方法都不同.It may be impossible to give each child a room to himself.不可能让每一个孩子都有单独的房间.Each apartment has one or two twin-bedded rooms.所有公寓套房都有一间或两间双人房.也可以说people or things each do something 或 each of them does something,两句意思相同.We each carried a blue marking pencil.我们每人都带一支兰色记号笔.There will be the benefit of the lower rates of tax for each of them.他们每个人都会得到较低税率的优惠.Each of the boys stood to earn as much as he used to.每个男孩都将能赚到不少于他们以前赚到的钱.