Stopwords

Most of the search engines including Google uses stemming technology. That is, 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.

Most probably, Google is using a lexicon (stopwords) for stemming, rather than a stemming algorithm.

The “stopwords” are common words generally ignored in query and sometimes not indexed.

Some of the stopword lists found are:

1. stopwords1
2. stopwords2