what is the difference between 之 and 其？”之“和“其”有什么区别？
Both have the same possessive he, her etc...
I have been seeing them in sentences but don't know when to use them. Are they interchangeable.

Question

Answer

三分之一： 1/3 one third

五分之四 ：4/5 [五个中的其中四个]

其他的=other
其实=infact
以其人之道还治其人之身【其=this, his,her,...】
攻其不备【其=he】
之乎者也（we use it to stand for old chinese, example： he says old chinese everyday他天天说之乎者也)

Answer

之 means “of” in most cases，while，其 means “this， those ，that， these， it or they”  “其中之一” means “one of these”

Answer

在用作代词的时候是可以互换的。
之的用途比其更广泛一些

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