ESL Mania - ESL Mania offers a wide range of vocabulary and grammar resources for adult learners and teachers. Resources include grammar explanations, quizzes, and book recommendations.
1-Language.com - This one-stop language site provides listening centers, flash games, grammar quizzes, word searches, and activities to help students improve their English grammar, vocabulary, and pronunciation.
ManyThings - ManyThings is a free EFL site that provides quizzes, games puzzles, and random information for improving your English. Within this site, students can find all the resources needed to improve and build vocabulary.
ESL Galaxy - This impressive ESL site offers over 2,368 worksheets for activities and lesson plans. The worksheets within this site can be used to improve grammar, vocabulary, conversations, and pronunciation.
About.com - About.com's Guide to ESL provides a number of vocabulary builders for EFL students. Beginner to intermediate students can find idioms, vocabulary lists, and vocabulary quizzes as well as tools for grammar and pronunciation.
BBC - BBC offers a unique feature to help students increase grammar, vocabulary, and pronunciation through the news, video, recording, and quizzes.
English Interactive - This interactive site features vocabulary builders through audio practice. English Interactive also offers links to reading and writing resources.
Eflnet - Eflnet is a site that offers tools for increasing your grammar, vocabulary, listening, and reading skills. The grammar page provides exercises, tutorials, and activities.
VerbaLearn - The VerbaLearn site provides free vocabulary studying techniques. Students will find study saving resources such as audio, video flashcards, puzzles, and review.
ESL Pod - ESL Pod provides free podcasts for improving your English. This site also helps improve your pronunciation and vocabulary through everyday phrases and expressions.
Dave's ESL Cafe - This online cafe offers EFL students several online language learning opportunities. Students can find a help center, hint-of-the-day, phrasal verbs, pronunciation power, quizzes, and idioms.
A4ESL.org - The A4ESL.org offers opportunities for students to increase their grammar and vocabulary through English and bilingual quizzes. This site also provides interesting puzzles and informative podcasts.
Radio Lingua Network - The Radio Lingua Network offers an innovative podcast for practicing phrasal verbs. This is a great way for EFL students to boost understanding and pronunciation.
Using English - Using English offers a large collection of grammar resources for students and teachers. Just a few of the resources students will find useful include a grammar glossary, irregular verb reference, and phrasal verb practice.
Randall's ESL Cyber Listening Lab - This free listening lab provides 20-minute vocabulary labs for intermediate level learners.
English English - English English provides links to some of the best grammar, vocabulary, reading, writing, listening, and speaking resources.
English as a Second Language - This site, created by Rong Chang Lee, Ph.D., offers a huge collection of podcasts, quizzes, games, and dictionaries for EFL students. A good pronunciation builder is the pronunciation page of this site which includes videos, exercises, tongue twisters, and software.
ESLTower.com - ESLTower.com offers printable and interactive grammar and vocabulary exercises for EFL students. These fun and easy resources provide the perfect opportunity for EFL students who are learning on their own.
EnglishClub.com - The EnglishClub.com offers free audio pronunciation builders. This language site also features grammar, vocabulary, listening, speaking, reading, and reference resources.
ESL Resource Center - This site, designed for English learners and teachers, offers lessons and exercises for improving grammar, reading, vocabulary, spelling, pronunciation, and listening skills. Students can also find resources for converters, games, and articles.
Guest post from education writer Karen Schweitzer. Karen is the About.com Guide to Business School. She also writes for OnlineColleges.net.