http://www.towson.edu/ows/moduleSVAGR.htm
Here's another way to look at it. This one includes quizzes to check your understanding.
You could print a quiz and take it our visa-versa. Turn it in for extra credit.
http://grammar.ccc.commnet.edu/grammar/sv_agr.htm
And another --
http://owl.english.purdue.edu/handouts/esl/eslsubverb.html
And another quiz -- (This could also be for extra credit. It's easier than the quizzes above.
http://www.eslcafe.com/quiz/sva1.html
This very clever cartoon is from www.andertoons.com.
Originally posted 5/19/11. Reposted 2-7-11.