Written By: Gaye Swan

A strong grasp of grammar is essential for a writer. Nothing is as unprofessional as misspelled words, missing commas, misplaced apostrophes, and wrongly-used words. While tools such as a computer’s spell check and apps like Grammarly can keep us on track, a good writer should have the skill set to write well without these aids. A list of all grammar rules would take too long to detail, even for a grammar nerd like me, so I’m listing a few that I’ve found most helpful over the years.

Commas

I’m a fan of the Oxford comma, the final one in a series of three or more: I ate blueberries, apples, and peaches. In fairness, I admit that AP Guidelines don’t require it. Named for the Oxford University Press guidelines that specify usage, the comma makes a list very clear. Consider two sentences that amusingly make the case for the Oxford comma:

I dedicate this book to my parents, Ayn Rand and God.

I dedicate this book to my parents, Ayn Rand, and God.

We invited the strippers, JFK and Stalin.

We invited the strippers, JFK, and Stalin.

If you chose not to use the comma, make sure you rearrange any misleading groupings like the ones above, and above all, be consistent!

A comma should not separate a subject from the verb:

My sister Helen, is a beautiful girl.

My sister Helen is a beautiful girl.

A comma is not needed to separate two actions:

Helen will play the piano, and sing.

Helen will play the piano and sing.

A comma is used to separate an introductory clause from the rest of the sentence:

After graduating with her doctorate in psychology, my sister Helen opened a clinic.

For shorter introductory clauses, a comma is optional. Just be consistent with usage!

In 2014 Helen graduated from college.

In 2014, Helen graduated from college.

Apostrophes

Apostrophes are used for two things: to show possession and to contract words. 

Contracted words include won’t, don’t, wouldn’t, I’ve, and you’d. Considered to be more informal, contractions should be used sparingly in professional writing. If you’re going for a friendlier vibe, such as a blog like this, contractions are fine.

Possessive words seem trickier to some of us. I’ve seen cards signed “The Smith’s” more often than I can count. The Smith’s what? I want to ask. If you are talking about more than one person, place, or thing, you need to use the plural form, not the possessive. “Greetings from the Smiths,” for example.

For singular words, add an apostrophe s: my daughter’s book. If you have more than one daughter, make the word plural, then add the apostrophe: my daughters’ books. If the Smiths are announcing a trip, they would properly say “the Smiths’ vacation.”

Style guides vary on what to do about adding an apostrophe to a singular word that ends in an s. When Charles is claiming his meal, the phrase can be either “Charles’ lunch” or “Charles’s lunch,” depending on which guideline you consult. I prefer “Charles’s,” but as always, pick one and stick with it throughout the body of the copy.

That or Which

When using a defining clause, use the word that. A defining clause gives information that is essential to the meaning of the sentence:

Books that include a good mystery are my favorite.

The word “which” introduces a non-defining clause. A sentence will make perfect sense without the clause.

The word “which” introduces a non-defining clause, which means the sentence would make sense without the clause. 

Online Resources

You can always use your preferred search engine to find resources for grammar rules. Here are a few I have found particularly helpful:

Grammarly has a very thorough selection of blogs on every conceivable grammar rule. 

StyleBlueprint’s Grammar Guru is both fun and helpful.

Copyblogger has several excellent blog posts on grammar; this one offers some great tips.

For professional writing, the AP Guidelines are the definitive style to follow. You can set up an account with the Associated Press and order a hard copy, or do what I did – download a .PDF cheat sheet.