to Grammar and Writing - The guide contains scores of
digital handouts on grammar and English usage, over 170 computergraded
quizzes, recommendations on writing from basic problems in subjectverb
agreement and the use of articles to exercises. [Acrobat Reader,
sound card, and PowerPoint recommended but not required.
Internet Grammar of English - Course written primarily
for university undergraduates but useful for anyone as it doesn't
presume any prior knowledge of grammar. Free for students who
log in from a UK university and all explanations are free.
Grammar - Games to test your English, a video grammar
lesson and more.
Writer's Guide to Prepositions - A reference book full
of the most frequently-used English words and their right prepositions.
Over 7,500 examples.