Ranking for keywords
 

How does Google distinguish between a word and its plural when ranking? My site http://www.Filthy-Frank.com ranks well for the keyword Gangbangs but does not rank well at all for Gangbang. Thank you

Google uses "stemming" technology to associate singular/plural/similar words. It's not perfect. My guess is that a combination of using a variety of both singular and plural forms on your page, as well has having inbound links which anchor from both forms would help increase your ranking for both. There are no concrete fixes.

Even with simply stemable words they are not equivalent. For example I might be #1 for "widget review" but nowhere for "widget reviews" or "widget reviewed".

Well yeah, that's the thread author's point, and mine as well.