There are some on-line possibilities for practicing English for ESL exams. UsingEnglish.com is a reliable source for English help. Along with a dependable Glossary of English Grammar Terms, they have a category for Tests & Quizzes. They also have a list for Toefl Vocabulary found under Check a Word's Grammar and Usage. There are also special sections on English Idioms, English Phrasal Verbs, and English Irregular Verbs. Under Articles, you'll find articles about English Usage.
Another source is EnglishClub.com. They have extensive lessons on English Grammar so you can study in any weak areas you may have, from modals to gerunds and everything in between. They also cover Vocabulary including Irregular Adjectives, Prefixes, Suffixes, and Contractions. They also have Listening, Reading, Speaking, and Writing in English Exercises.
For improve your English you can go to these sites:
- http://a4esl.org/ [This has grammar and vocabulary quizzes for beginner, middle and advanced learners.]
- http://www.goenglish.me/ [You must register with the site, but the lessons seem to be free.]