Digital Education Network (EDUNET): Online English Grammar
A fairly comprehensive online grammar plus some grammar practice activities.
EDUNET: Online English Grammar Clinic
Send your grammar questions and get an answer from an expert. Run by Lydbury English Centre in the UK.
A collection of interactive multiple-choice quizzes, mostly on grammar. Written by John Wong at the Language Institute, City University of HK.
Cobuild Idiom of the Day
A new idiom each day from the Collins Cobuild website.
Dave's ESL Cafe Idioms Page
Idioms plus a definition. You can get idioms at random or view the entire list.
Hundreds of varied vocabulary quizzes for all levels from the Internet Teachers of English as a Second Language (TESL) Journal.
Word for Word
A fascinating website dedicated to unusual words and phrases. Only suitable for advanced English students.