The 10 most common grammar & AP Style mistakes, plus the importance of using AP style

Is it sad that when I saw this topic in our blog list I got just a little giddy? I’m very much a grammar nerd. I cringe while reading most Facebook posts, using every bit of willpower to ignore the need to correct the poster. I’m the person my friends and (previous) co-workers will ask to edit something, and I’m usually the first to start rattling off letters when someone asks how to spell something. Interestingly enough, I was an English major before switching to journalism, so there were many habits I had to change to become compliant to the AP Style gods. Here’s a list of some egregious grammar issues and AP Style errors.

That vs. which

This is one that still trips me up. That is used for essential clauses (the sentence would lose its meaning without the clause) and doesn’t use commas. Which is used with nonessential clauses (meaning the sentence doesn’t lose meaning without the clause) and uses commas. I came up with a little rhyme to help with this; use that when you have to have it, use which when you can ditch it.

Its vs. it’s (plus their vs. there vs. they’re and you’re vs. your)
This is a simple one that drives me up the wall. It’s is a contraction of it is or it has and its shows possession. Along this same problem area: their shows possession, there is a place, they’re is a contraction of they are, you’re is a contraction of you are, and your shows possession. Get it? Got it? Good.


It’s always toward, without an “s.” Never add an “s” to toward, ever.

Punctuation with quotation marks

Periods and commas always go inside the quotation marks, whether they’re punctuating the quote or the flow of the sentence. Dashes, semicolons, questions marks and exclamation points only go inside the quotation marks if they directly apply to the quote, otherwise they go outside the quotation marks if punctuating the whole sentence.

Months, days and seasons
Only abbreviate months if used with a specific date, otherwise spell it out. Also, only the following months should be abbreviated and in this way: Jan., Feb., Aug., Sept., Oct., Nov. and Dec. If you’re writing for tabular material, the following forms are acceptable, without a period: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov and Dec. Likewise, only abbreviate days of the week for tabular material, without periods, as so: Sun, Mon, Tue, Wed, Thu, Fri and Sat. Seasons are not capitalized unless they are part of a formal name.

Titles (formal)
I’m talking about mayor, sheriff, chairman of the board, president of the United States, etc. Essentially, only capitalize a formal or working title when it comes before the person’s name, otherwise it should be lowercase. The rules vary when you start to talk about military titles, royal titles, long titles, short titles, etc. The AP Style guide has a whole page about formal titles, so check it if you’re in doubt about how to properly address someone in print.


The AP Stylebook has about a page and a half dedicated to numbers. In general, spell out the numbers zero through nine, and use the number for 10 or more. Try to avoid starting a sentence with a number, but if need be, spell it out, unless it’s a calendar year. There are a number of rules regarding decimals and numbers in a series, so check out the Stylebook for more detailed rules.

State abbreviations
Be wary, the postal code abbreviation and the dateline abbreviation will most likely be different. Plus, there are eight states that aren’t abbreviated in datelines, listed here: Alaska, Hawaii, Idaho, Iowa, Maine, Ohio, Texas and Utah. The District of Columbia is also not abbreviated in the dateline. Only use the postal code abbreviation with addresses.

Commas in a series
Ah yes, lastly, but definitely not least, the Oxford or serial comma. The habit that many an English teacher probably propelled you to develop. It’s amazing how passionate people are about their punctuation. People seem to either love or hate the Oxford comma, and the AP Stylebook is part of the latter group. Don’t use the Oxford comma in a simple series before the conjunction. Only use it to avoid ambiguity, if part of the series contains a conjunction or if you have a complex series of phrases. I was a fan until I realized it wasn’t AP Style, all hail AP Style…

Honorable mention
a.m. and p.m.  – That’s how they’re used. The periods may seem picky, but they’re proper. Also, try to avoid “10 a.m. in the morning,” or “10 p.m. tonight,” as it is redundant.

These aren’t life-altering changes, so what’s the big deal? You got into journalism because you want someone to read your work, right? AP Style is the Bible as far as the journalism industry is concerned. If your work isn’t in AP Style, it isn’t going to get read. It’ll be thrown in the trash, or become fodder for the office to laugh at, and maybe even live on in viral infamy online. So do yourself a favor, buy the book or the online membership, and become very, very close friends with it; your livelihood depends on it.