"In regard to" or "in regards to"

Is it incorrect to say either of the following?

In regards to your previous email

In regards to your previous emails

I was asked this by a non-native speaker, and after thinking about it I decided that in regards to sounds more natural than in regard to. Google confirmed that I have the same intuition as most speakers by returning 73 and 110 million results for the singular and plural expressions respectively.

I came here and found the related question What alternative would you suggest to "in/with regard(s?) to"? Although my question was asked as a part of that, no one gave much of a defense of their opinion. The closest was this comment:

No, I think that's just wrong. You have to watch out, people love to make up "just so stories" about grammar. This arises in part from the very common misapprehension that all points of grammar make some kind of rational sense, when in fact a lot of the details are purely conventional. For instance, you can still say "In regard to the strawberries..." The plural there is just another (probably incoming) variant. If you don't want pedantic people to be irritated with you, then by all means don't use it. – Alan Hogue

Is this a case where the most common intuition is wrong? Can someone better explain the rationale behind the use of the plurals?

A comment mentioned Google Ngrams and I'ved posted the graphs below. In my opinion, Google search results or any other kind of Google result are only misleading if you're taking it to imply something more than what they're giving - raw data from some source.

Firstly, here are both in regard to and in regards to in the same search. The plural doesn't show up because it's so low.

Now here is just "in regards to" in its own graph so we can see it.

I suppose I should refrain from offering interpretation. I'd like for people to do that in their answers. Nonetheless, this does absolutely beg for certain conclusions to be drawn.

As a final note, Google Trends shows in regards to winning out of the two with about the same ratio as the search results.

Solution 1:

We should use in regard to something or with regard to something. Here regard is an uncountable noun meaning attention to something.

However we use as regards something because here regards is a verb meaning to look at something.

Solution 2:

The OED describes in regards to as regional and nonstandard.

Solution 3:

Both of your "in regards to" examples represent "non-standard usage", i.e. are widely perceived as incorrect.

Regarding your claim that "Google confirmed that I have the same intuition as most speakers", merely comparing raw numbers of Google hits is too thin a basis to be called confirmation. The bulk of hits on the leading pages of the searches are pages either decrying use of "in regards to", or correctly using "in regard to", or multiple hits to incorrect (but influential) usage in song lyrics.

Regarding past usage, use of the phrases in printed books is reflected by an ngram at this link. It shows that "in regards to" has no more than a trace of usage in printed works, while "in regard to" is used hundreds of times more frequently.

Here are some links to authoritative comments about use of "in regards to":

• dailywritingtips notes that "The Chicago Manual of Style places “in regards to” in its section on “good usage versus common usage”, and then quotes CMS: "in regard to. This is the phrase, not “in regards to.” Try a single-word substitute instead: about, regarding, concerning." dailywritingtips goes on to say that "The Oxford English Dictionary lists “in regards to,” but labels it “regional and nonstandard” and quotes "The Columbia Guide to Standard American English to similar but stronger effect, as in next item.
• englishforums quotes from Kenneth G. Wilson's The Columbia Guide to Standard American English, 1993: "In and with regard to, regarding, and as regards are all Standard, synonymous prepositions, slightly longer and more varied than but meaning much the same as about and concerning: […]. In regards to, however, is both Substandard and Vulgar, although it appears unfortunately often in the spoken language of some people who otherwise use Standard. It never appears in Edited English."
• Entry 18 at dictionary.reference says, in part: "In regards to, and with regards to are widely rejected as errors."