each other ,one another是相互代词,译成“互相”,可以通用。each other表示两者之间,而one anther表示许多人之间。它们有所有格形式each other’s ,one another’s。如: We must help each other when we are in trouble.(我们身处困境时要互相帮助。) / They sat there without talking to one another / each other.(他们坐在那儿,互相都不说话。)
Who(m) did you invite to your birthday party?(你都邀请了谁参加你的生日聚会的?) / What does she want to be when she grows up?(她长大了想干什么?)
2.who 和whom只能独立使用,其中who可以作句子的主语、表语或动词的宾语,whom只能作谓语动词的宾语;而what、which、whose等既可以独立使用作主语、表语和宾语,也可以与名词构成疑问短语。如: Who is that man?(那男的是谁?) / What colour are their hats?(他们的帽子是什么颜色?) / Which car was made in Germany?(哪辆车是德国造的?)(被动句)