Particle に and は


In Kanji in Context book, there's this one sentence:

> 人間に上下はないと考えるアメリカ人にとって、日本の目上と目下の関係は面倒だろう ?

I'm not sure why に and は and not が。 The second part of the sentence is
understandable, but the first one makes no sense to me. I'm not sure what 上下
means either in this context. The reference book says "up and down" or "top
and bottom," but I can't grasp the meaning.




First, 上下 means higher and lower social status (such as sempai and kohai)

The reason に is used in this case is because は is being used after 上下 for
emphasis. You can't use は twice in the same phrase. Also the phrase is being
used to describe the subject アメリカ人

If you are confused about the descriptive phrasing, here are more examples:

>   1. ごめんなさいと言えない人とは友達になりたくない  
>  I don't want to be friends with people who can't say they are sorry.
>   2. 納豆が嫌いな人はたくさんいる  
>  There are many people who hate the smell of natto.
>   3. 日本語が読めない外国人には日本で良い仕事は見つからない。  
>  For foreigners who cannot read Japanese, it is difficult to find a good job
> in Japan.
>

