关于 vs 对于 vs 至于

Three ways to change the subject

• All three touch "about / regarding" — but do different jobs.
• pertaining to关于guān yú = about (a topic / scope), often opens the sentence.
• regarding对于duì yú = regarding (the target of an attitude). as for至于zhì yú = as for (switching to a new sub-topic).

pertaining to关于guān yú (topic) vs regarding对于duì yú (target)

• pertaining to关于guān yú这件zhè jiànmatter事shì = about this matter; regarding对于duì yúthis这个zhè gequestion问题wèn tí，I / me我wǒto have / there is有yǒuway of looking at a thing看法kàn fǎ = regarding this issue, I have views.

about关于guān yúthis这zhè(measure word)件jiànmatter事shì，I我wǒnot不bùclear清楚qīng chu。

• pertaining to关于guān yú这件zhè jiànmatter事shì，I / me我wǒnot不bùclear清楚qīng chǔ = "about this, I'm not clear."

as for至于zhì yú = as for (a new sub-topic)

• as for至于zhì yúprice价格jià gé，after以后yǐ hòuto say again再说zài shuō = "as for the price, we'll discuss it later."

as for至于zhì yúprice价格jià gé，later以后yǐ hòuagain再zàidiscuss说shuō。

• as for至于zhì yúprice价格jià gé，after以后yǐ hòuto say again再说zài shuō = "as for the price, later."

Recap

Read the full reference: HSK 5 grammar — Comparing similar prepositions.