Encyclopedias

• Simple English Wikipedia - A version of Wikipedia for adults who are learning English
• Wikipedia
• World Book Encyclopedia

Free Online Dictionaries and Spelling Tools

• Cambridge Learner’s Dictionary - Includes idioms, grammar, English-Spanish, and Spanish-English
• Dictionary.com
• Merriam-Webster Learner’s Dictionary
• Merriam-Webster Visual Dictionary Online
• WordReference.com - Includes multiple bilingual dictionary choices

Grammar and Writing

• Busy Teacher - Free worksheets on grammar, vocabulary, and other subjects
• English Club
• English for Everyone - Printable English grammar worksheets
• English Grammar Exercises - Online exercises and downloadable worksheet organized by level of difficulty
• OWL Purdue Online Writing Lab
• Perfect English Grammar - British site that includes downloadable PDFs, videos, and quizzes
• Road to Grammar - Contains quizzes that students can take online or downloaded as PDFs

Reading and Vocabulary

• English Club
• Vocabulary.com
• BITS English Language Learning - Collection of read-along novels, novellas, and short stories

Idioms

• In The Loop (PDF) - A Reference Guide to American English Idioms

History

• Khan Academy - Offers practice exercises, instructional videos, and more
• About the USA (PDF) - Examines the customs, government, and history of the United States
• Voice of America - Audio programs and captioned videos on U.S. History. Articles use vocabulary at the intermediate and upper-beginner level. Audio programs read 1/3 slower than typical English speed

Math

• Khan Academy - Offers practice exercises, instructional videos, and more
• Cymath - Includes problem solving calculator and practice problems
• Skillswise (BBC) - British site with free math videos, games, and quizzes
• Space Math @ NASA - Math problems with a space/astronomy focus, for Grades 3 through Calculus
• Webmath - Generates answers to specific math questions entered by a user and shows the student how to arrive at the answer

Adult Education Centers

• LAUSD Adult Education, Career, and Occupational schools

Online Tutoring

• Free online tutoring in math, science, English, social studies and writing. Help with citizenship and TOEFL test preparation is also provided.