Ancient attitudes to grammar still survive: many people are in awe of it, know little about it, tend to fear or dislike it, often find it baffling or boring if exposed to it at school, and yet a minority is fascinated by it: a field in which precise scholarship and nit-picking pedantry have co-existed for centuries.
(Sidney Greenbaum, The Oxford English Grammar. Oxford University Press, 1996)

Let's say you've been out of school for a few months--or even a few decades--and you'd like to review the basic principles of English grammar.

Here are five recently revised articles that will help you get started.

1. What Is Grammar?
   Descriptive grammar refers to the structure of a language as it's actually used by speakers and writers. Prescriptive grammar refers to the structure of a language as certain people think it should be used. Both kinds of grammar are concerned with rules--but in different ways. . . . Read more
2. What Are the Parts of Speech?
   Part of speech is the common name for a word class--a category into which words are placed according to the work they do in a sentence. Here you'll be introduced (or reintroduced) to the eight traditional parts of speech. . . . Read more
3. Grammar Basics: Sentence Parts and Sentence Structures
   Experienced writers understand that the basic parts of a sentence can be combined and arranged in countless ways. So as we work to improve our writing, it's important to understand what these basic structures are and how to use them effectively. . . . Read more
4. The Top 25 Grammatical Terms
   Active and passive voice, direct and indirect objects, compound and complex sentences: you've probably heard these terms before. Some you still remember, and others--well, others may not be quite as familiar to you as they used to be. If you're in the mood to brush up on your grammar, this page is for you: brief definitions and examples of 25 common grammatical terms. . . . Read more

1. Why Should We Study English Grammar?
   If you're reading this page, it's a safe bet that you already know English grammar. That is, you know how to add the right endings to words and put those words together in a sensible order. But how much do you know about grammar? And, really, why should anybody bother to learn about grammar at all? . . . Read more
    

Next, to review some of the guidelines, rules, and phony rules of English usage (that is, prescriptive grammar), here are a few good starting points:

• What's the Difference Between Grammar and Usage?
• Glossary of Usage: Index of Commonly Confused Words
• Five Phony Rules of Writing