Learner's Dictionary: This free online dictionary was created for English Language Learners.  The definitions are student friendly and give ample examples of how to use the vocabulary word correctly.

English as a Second Language: Jumbled Sentence Exercises:English as a Second Language: Dictation Exercises for English LearnersActivities for ESL Students: This site includes exercises, puzzles and quizzes to help students learning English as a second language. The content is contributed by teachers and categorized by language and difficulty level.

20-Minute ESL Lesson: This site contains a series of English vocabulary exercises designed to be completed in 20 minutes. Each lesson includes listen and repeat audio, a quiz and a follow-up activity.

Vocabulary.co.il: This site helps ESL students learn English vocabulary through a series of games. Games are categorized as slangs/idioms, analogy, contractions, etc.

English as a Second Language: Sentence Structure Writing Practice
This site allows students to test their English comprehension and writing skill by rearranging words to form sentences. Students must not only rearrange the words, but also use proper capitalization and punctuation.

English as a Second Language: Jumbled Sentence Exercises: This site allows ESL students to test their word knowledge by rearranging the given words to form a sentence.