16 Quick and Free Grammar and Usage Resources

At 3 a.m., while polishing an email blast for your customers, you get a brain freeze about a grammar question. For instance:

• Should it be “their’s,” “they’res,” “there’s,” or “theirs”?
• Which punctuation mark (if any) does a certain sentence need in the middle?
• Do we capitalize “French” in “French cuffs”?

Use the free online resources below to answer such questions quickly.

Grammar Rules

GrammarBook.com. If you know what kind of rule you’re looking for and need a quick refresher, consult this well-organized online reference. But if you don’t already know the terminology of, say, a colon (two dots on top of one another) and a semicolon (a dot above a comma), this site may be frustrating to use.

Guidelines for Using Capital Letters. An excellent and up-to-date rundown of the rules for using and not using capital letters, with dozens of helpful examples.

Subject-Verb Agreement. This page helps you figure out whether you should write, say, “is” or “are” and “has” or “have.” It answers questions such as does “committee” take a singular or plural verb? What about “scissors,” “mathematics,” and “everybody”?

Personal Pronouns. Here you can quickly review whether it should be “the teacher and me” or “the teacher and I.” This is a classic trouble spot even for well-versed English speakers.

Punctuation and Spelling

The Punctuation Guide. Consult this site first if you’re not sure what the various punctuation marks are called. Proper use of each one gets explained clearly, with examples. The site’s “Top Ten Tips” section provides a handy review of punctuation essentials, and “Other Matters” offers an excellent summary of the differences between British and American punctuation rules.

The Punctuation Guide provides this visual reference of punctuation marks, eliminating the need to know their names to look up the proper usage.

Bacon Punctuation. Confused about commas? Or about question marks? This infographic provides a humorous example of each punctuation mark in English — from apostrophes to semicolons. No grammar knowledge needed.

Hyphen Help. Even professional editors sometimes need a refresher on which word combinations need clarifying hyphens and which do not. If you’re befuddled on whether it should be “accident-prone” or “accident prone,” “build up” or “build-up,” consult this page.

Spelling Rules. Even though English spelling is notoriously inconsistent, it does have some rules that are useful to know. This page explains them clearly, with examples.

Common Writing Errors

Paul Brians’ Common Errors. This site by a professor at Washington State University doesn’t require a knowledge of grammar terminology. You can simply look up a word or phrase you have a question about, such as “could of,” “no one,” and “they’re, their, or there.” His explanations are easy to understand, well informed, and sometimes witty.

Notorious Confusables. Should it be “accept” or “except”? “Devise” or “device”? “Faze” or “phase”? This 1980s-era set of reference pages settles the score on commonly confused words. It includes sample sentences that illustrate how to use each member of a notorious pair. The site is quick, intuitive, and handy, requiring no knowledge of grammar terms.

200 Homonyms and Homophones. This page provides a quick reference on English words that sound the same but are spelled differently, such as “aisle” and “isle,” “ceiling” and “sealing,” and “waist” and “waste.” Each option is succinctly defined to clarify.

Test Your Knowledge

Try Finding the Mistakes. See if you can spot the 28 punctuation, grammar, capitalization, and usage errors in this little quiz made up of typical business emails.

Grammar: Quiz Yourself. This 19-page downloadable PDF booklet covers a lot of tricky areas where many people get grammar points wrong, including structural flaws in sentences, pronoun and verb inconsistencies, and punctuation. Each section begins with a short diagnostic quiz. Then you get the answers and explanations, along with some practice sentences to assess whether you can apply the rules correctly.

Test Yourself: Commonly Confused Words. Discover how well you know the difference between common word pairs, such as “except” and “accept,” “role” and “roll,” “personal” and “personnel.” Get at least 20 of the 26 quiz items right and you deserve a gold star.

Self-Test for Commas and Periods. Do you know the correct use of commas and periods — also known as “full stops”? Quickly find out.

Finally, How Much Does This Matter? This interesting resource sorts common grammar mistakes into those that make you look stupid, others that make you look careless, and errors that you can probably get away with.