This website written by one English as a Second Language teacher outlines how to effectively teach English grammar.
This section of the ESL website contains information on the main differences between English and some of the other most widely-spoken world languages (Arabic, Chinese, Dutch, French, German, Japanese, Korean, Portuguese, Spanish...). For each language this website outlines the differences between that language's grammar and English grammar.
This article outlines some of the major differences between English and Chinese grammar and some of the most challenging parts of English grammar for native Chinese speakers.
This website hosts several grammar quizzes for extra grammar practice for English as a Second Language Learners.
This website is a resource for ESL students to learn and practice English grammar and writing. Specifically students can practice sentence structure, paragraph formation, and how to write an essay and research paper.
From the esteemed writing resource A Writer's Reference, a list of online resources for nonnative English speakers