GRAMMAR

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.

Interactive Quizzes
A collection of interactive multiple-choice quizzes, mostly on grammar. Written by John Wong at the Language Institute, City University of HK.

VOCABULARY

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.

Vocabulary Quizzes
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.