Throughout history, Vietnam once developed a word system that was similar with Chinese characters, the so-called "square" words in form, but with different writing and meaning.  The system has been obsolete and replaced by a Roman alphabetic one.

Nevertheless, Vietnam is in the south of Five Hills area, I think the diction of spoken Vietnamese must be something in common with the dialects of southern China.  The attached video shows a Vietnamese girl recites the famous 《岳陽樓記》with her language.  Does it sound a kind of kinship?

https://www.ixigua.com/7142436962677621260?logTag=9b9b0cc6b4e0ec52cb10 

PS I did translate 《岳陽樓記》  in my previous writing long time ago at https://classic-blog.udn.com/kkuo0810/7615885