Hi David

Quite a lot of the sites I monitor have both the plural and singular versions of certain keyphrases amongst their targets. The majority of them use the plural forms more often in their content. At one time you could use on or the other and almost automatically rank for both.

However in the last couple of years I've noticed a number of occasions when the singular version has suddenly dropped way down while the plural remains highly ranked. Sometimes it slowly climbs back up again but never quite regains its former positions. It happened again recently - again across a number of different sites for different keywords - and I'm of the opinion that it's a Google algorithm tweak. (Coincidentally I blogged about it this week.)

In my cases we've left it alone as the plural is the form that makes most sense (and generally has the higher search numbers) but I suspect that if we were to target the singular form with enough text content and anchor text we could probably get them back.

Does your content concentrate on one or the other or is it equally spread?

cheers

Bill Marshall