http://www.pdictionary.com

http://www.englishclub.com/esl-games/matching.htm These are online games of varying levels, all done in the form of a match game. They work on vocabulary, grammar, and general knowledge.

http://www.starfall.com This is actually for early readers, but it practices vowel rules and reads words and sounds out words in stories or with picture clues. It would help those with NO English get started.

http://www.inglesmundial.com/index.htm This is a great site for Spanish speakers and others who are just beginning to learn English. The beginning level has directions in Spanish. Levels two and three are fine for anyone since the instructions are given in English.