Difference between "regard of" and "regard to"

Question

I want to apologize in an official letter. Do I start it with "Apologizing in regard of this incident" or "Apologizing in regard to this incident"?

Answer 1

"regard of" is not common - I am not sure if it is actually grammatically wrong, but it's awkward. I would actually use "concerning" rather than any version of "regard", but that is more a preference; I'd rather use one word than three.

Answer 2

"In regard of" is not natural English at all. There is debate about "in regard to" vs. "in regards to."

However, a much better way to say this is "I wish to apologize for the incident . . ." or even "I apologize for my behavior . . ."

Answer 3

With regards to...

Is probably preferred.

In regard to...

Can also work.

Answer 4

"In regard of" is not grammatically wrong at all. There are examples of use which date back to the nineteenth century [please see: https://books.google.com.br/books?id=E-BhAAAAcAAJ&pg=PP9&lpg=PP9&dq=%22in+regard+of%22&source=bl&ots=ftxGKH1kvF&sig=mJ4NFxXWf9IOcoIB6BsH-APCyRo&hl=pt-BR&sa=X&ved=0ahUKEwjbuLz54YvWAhWoiFQKHR_HDHsQ6AEIYDAJ#v=onepage&q=%22in%20regard%20of%22&f=true , and https://books.google.com.br/books?id=TFZiAAAAcAAJ&pg=PA19&lpg=PA19&dq=%22in+regard+of%22&source=bl&ots=7o9IM5flPt&sig=OvUceL4tpGAzqSn6VGKEsG0WM2U&hl=pt-BR&sa=X&ved=0ahUKEwjbuLz54YvWAhWoiFQKHR_HDHsQ6AEIWjAI#v=onepage&q=%22in%20regard%20of%22&f=false ].

Personally, I believe that the expression would fit beautifully in formal writing. But, in this case, I would advise against the use of "Apologizing", hence that construction strikes me as modern by comparison and in conflict with the style. Therefore, I would rewrite it as:

"To apologize in regard of that incident" ...

or [if the original line of thought was to use "Apologizing" in the Present Continuous tense]

"As I apologize for the incident" ....

or

"In regard of the incident, I offer my [sincere] apologies," ...