Hi Big heart, both , liǎng gè dōu / liǎng zhě dōu , 两个都 / 两者都 each , měi gè , 每个 each other , hù xiāng , 互相 either , yě / rèn yì yī gè , 也 / 任意一个 everybody , měi gè rén , 每个人 everyone , měi gè rén / měi yī gè , 每个人 / 每一个 everything , měi jiàn shì , 每件事 I hope my answers can be useful for you to understand these phrases. If you have any problems about Chinese, just let me know. ^_^ Anna

both = 双 = shuāng each = 每 = měi each other = 互相 hù-xiāng either = 或者 = huò-zhě / 还是 = hái-shi everybody = everyone = 每 个 人 = měi gè rén everything = 什么 都 = shén-me dōu

both 两个都 each 每个 each other 互相 either 任意一个 everybody 每个人 everyone 每个人 everything

everybody：mei ge ren(tone is 3.4.2)每个人 everything：mei jian shi（tone is3.4.4.）每件事