Automatic Stemming. Google is now doing automatic stemming on difficult searches. For example, when you search "pearls rings", Google searches for variations of your search terms and returns results with the word "pearl" and "ring", not just "pearls rings".

Word Variations (Stemming)

Google now uses stemming technology. Thus, when appropriate, it will search not only for your search terms, but also for words that are similar to some or all of those terms. If you search for "pet lemur dietary needs", Google will also search for "pet lemur diet needs", and other related variations of your terms. Any variants of your terms that were searched for will be highlighted in the snippet of text accompanying each result.

Read about google search »