How to know when do use singular vs plural in anchor text and on-page copy?

[JDatSB]

I'm building out a specific section of our site and I want to make sure I target it correctly.

Is there a rule of thumb when to know how to use "car" vs "cars"? (as an example)

Is there a specific way to research the right approach?

thank you!

[GregB123]

When the plural is made by just adding an S, then Google seems not to differentiate the singular or plural. You can verify it by opening two windows and searching for the term both with and without the S and seeing if the results are ranked differently.

But if the plural is a whole different word, like Goose and Geese or Mouse and Mice, then you will definitely have to makes a decision on which to use.

[JDatSB]

I did a search for "car" vs "cars" and I see a drastically different number of results.

3.3B vs 1.5B, respectively.

Do you have any research to support your response?  Just curious where you're getting your information from.

[GregB123]

No research. Just memory of doing searches with and without an S for my own keywords and noticing that the results were fairly similar.

I just checked garden and gardens - many of the page 1 results are the same.

Then I checked tool and tools - very different results because of the band "Tool"

Checking garden tool and garden tools takes it back to many similar page 1 results.

The original poster just asked for a Rule of Thumb. So perhaps the answer is "It depends on the keyword. Google it and see what happens."

[Everett]

A lot of results for singular/plural and synonyms are so similar as to be nearly identical for the first page or two, which is what really matters, and which is what  Gregory Baka is referring to. You will notice a lot of times if you search for something you'll see synonyms and variants bolded in the description and title in the SERPs. That would be your signal that one is being treated as synonymous with (though not "identical to") the other.

In terms of singular vs plural I tend to include both variations naturally within descriptions and on-page copy. External links tend to contain both versions too unless you're buying the anchor text. I would think, based only on common sense and experience, and not any quantifiable study, that Google looks for a natural variation. If you have two different landing pages, one targeting singular and the other targeting plural, that would not only be wasting effort, money, link equity, etc... but it would seem very unnatural. If I were writing an algorithm I'd probably figure out a way to push such pages lower in the results unless other signals point to really high quality at the page and/or domain level.

ALL of this "common sense" stuff flies out the window though when any ambiguity of intent or results is involved. For example, with "cars" you could be talking about the animated movie, which is why you see IMDB, Disney and Wikipedia  in the results. This disambiguation factor is why Google is pushing for semantic markup of the web, and is probably why topic modeling has become increasingly important (e.g. want to rank better for "cars" when the user intent is to find the animation, use words like "Pixar" and "Lightening Steve McQueen" in the copy).

As a rule of thumb, I tend to go with whatever sounds better and makes more sense to the user. For example, on a category page I might write "blue widgets" in the title, but I'd use "blue widget" on a single product page. From there I go with what the data says. Looking at Analytics a few months later I pay attention to traffic and keywords as a follow-up. If the "blue widgets" category page gets 80% of it's  traffic from a #3 ranking for "blue widget" when it ranks #1 for "blue widgets" that tells me I should probably change the title to the singular version.

In the end I usually find I get the best results when I don't think too hard about it and just go with my gut when writing. I know that's not scientific or anything, but if it works it works.