答：所有格 each other's 后面的名词用单数还是复数？
我们认为：each other's后面可以后接单数名词，不可数名词以及复数名词。例如：
Many couples could not even speak each other' s language.
Lisa and Nicole were at each other's throats the whole trip.
We read each other' s thoughts and share each other's interests.
关于each other’s 后接可数名词用单数还是复数，我觉得需要根据逻辑判断。例如下句：Some neighbours cut each other' s lawn while they're away so the grass doesn't grow too long.
邻居互相帮助，你出远门，我帮你割草坪，我出远门，你帮我割草坪。
割草坪时的草坪总是单数概念。如果是同一天，你割我家的草坪，我割你家的草坪，两个草坪在被割，自然用复数了。
您好，要加单数。
