In Learning English: Meryn Stol voted up this answer. Aaron Knight Depending on your level of advancement, here are some of the best: google.com/dictionary - Google's dictionary is very good. It's based on the Collins Cobuild learner's dictionary. phrasemix.com - For learning natural conversational English. (disclaimer: I'm the author of this site.) americancorpus.org/ - For advanced English learners, this is an amazing tool. Type in a word or phrase and find examples from natural sources. lang-8.com - Write a journal entry in English, and other English-speaking users will correct your writing in exchange for help in your native language. rhinospike.com - Post some English text, and English-speaking users will record themselves reading the text out loud. youtube.com - There are videos on every imaginable topic. You can also do a search specifically for videos that have English captions. At higher levels, reading and listening to authentic English is best. You can do this on sites that... - Meryn Stol