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Esl Desk: Esl Drills & Quizzes
Vocabulary and grammar drills including quizzes on commonly misspelled words, irregular nouns and more. Quizzes range from beginning to advanced.
English Club
English Club: Esl Games: Matching Homophones
Follow links to 46 different homophone matching games. Links are divided into elementary, intermediate, and advanced. Answers can be checked when completed, and a percentage scores are displayed.
Other
Using english.com: English Grammar Quizzes & Worksheets
A nice treasure trove of printable grammar worksheets organized by proficiency level: beginner, intermediate, and advanced. Emphasis is on parts of speech but you'll also find some that focus on common spelling issues and vocabulary...