English as a Second Language (ESL) / Foreign Language (EFL)

A dropdown box allows users to choose from among the following Cambridge dictionaries: Advanced Learner's, Learner's, American English, Idioms, and Phrasal Verbs.

This dictionary can be searched by individual word or browsed by topic, and includes audio pronunciations for selected words and sentences.

In addition to a dictionary of American English for ESL / EFL students, this site includes a Learner's Word of the Day, pronunciation exercises, quizzes, and an Ask the Editors blog dispensing language advice.

This site features the online version of Merriam-Webster's Collegiate Dictionary, Eleventh Edition. The site also includes links to a visual dictionary, word puzzles and games, and the Word of the Day.

This site is excellent for learners of English. In addition to clear definitions, each word is accompanied by examples of usage, synonyms, and an audio of how the word is pronounced. The site also includes vocabulary lists, articles on English, and "The Challenge"-- a vocabulary learning feature that keeps track of your progress.

WordReference consists of free bilingual dictionaries, including these dictionaries from Oxford: English to Spanish, Spanish to English; English to French, French to English; and English to Italian, Italian to English. In addition, WordReference features Language Forums, in which non-native speakers can ask native speakers their grammar and vocabulary questions. Forums currently exist for English, German, Dutch, Spanish, French and Italian.