Jose Carrillo has written an excellent series of books on writing in English: 10 Most Annoying English Grammar Errors, English Plain and Simple, and Give Your English the Winning Edge; you can order them from the Manila Times website. He also manages the Jose Carillo's English Forum website.

Consult this guide to verb tenses for help with choosing the most appropriate verb tense to use.

Purdue University's Online Writing Lab is another good Web resource.