each of them+单三还是原型能换成every吗?

each of them+单三还是原型能换成every吗? each of them后跟动词三单形式还是复数形式? Don' t let the student _ (do)lots of homework.单三还是原型? each of them算单数还是复数 Each of them are还是is clever. i like neither of them...能换成i do not like both of them吗 Words and expressions in each unit 能换成every unit吗 in each and every one of them这句话对吗 each side of the road,还是every both of them能换成both them吗?另外both是什么词性? half of +可数名词+（动词原型or三单） either of them 和 each of them