Idk what you mean by “emphasis”, but there is no difference between proper nouns and common nouns. I mean, there is italics and bold if written digitally. Or underlining it if written on paper.
I THINK THEY’RE ASKING HOW YOU WOULD WRITE SO AS TO GIVE THE IMPRESSION THAT THE SPEAKER IS YELLING
I THINK THEY’RE ASKING HOW YOU WOULD WRITE SO AS TO GIVE THE IMPRESSION THAT THE SPEAKER IS YELLING
對唔住，漢字冇大寫子，用 BOLD 就得啦
(Sorry, Chinese Characters do not have capitalized characters, just use bold)
明唔明？
(Get it?)
If the site doesn’t show bold, then:
注意！
＊＊＊重要消息係呢度！！！＊＊＊
明唔明？
Attention!
*** Important Message Here!!! ***
Get it?
This works too.
(Note: I do not browse Chinese internet often, but this is what I would personally use to highlight it)