Grammar Girl here.

Today's topic is subject-verb agreement, and I'm doing something a little different. This week I have a guest writer for the show, my long-time copy editor Bonnie Trenga, the author of The Curious Case of the Misplaced Modifier.

But first, it's free audiobook time again compliments of Audible.com, the Internet's leading provider of spoken word entertainment. Get a FREE audiobook download of your choice when you sign up today. For details, log on to audible.com/grammar.

Oh, and I have to correct an error. Last week in one of the Web addresses I said, "Backslash, backslash," which many of you told me is just plain wrong. So I apologize. There are no backslashes in URLs.

Now, let's learn now to boost your immunity to the illness that kills your credibility: subject-verb inflammatory disease.

Good grammar instincts never die—even when the grammarian is lying dazed on a hospital gurney. As I was being rolled to the OR early in my copy-editing career, a grammar error jumped out and got me. When I pointed a weak finger and gasped sharply, my husband must have thought I needed more morphine. A blue sign dared to warn: “The use of cell phones and pagers are prohibited.” “Oh,” thought my relieved hubby. “Just a subject-verb agreement problem.”

I don’t have to look far to find agreement mistakes, even when I’m not in copy-editor mode. I was on hold for my doctor’s office the other day and winced when a sincere voice requested, “Your patience and consideration is very much appreciated.” I did not appreciate that at all, and my patience was as sore as my throat.

I suppose I should go easy on these misinformed medical types. After all, they’re interested in healthy organs, not healthy grammar. If you’re a writer type, though, you don’t want to come down with disagreement-itis. This debilitating ailment afflicts even the best writer, so you’re not immune. If you’re in a hurry, you don’t pay enough attention, and that’s when disagreement-itis strikes. It’s a deadly disease because it kills your credibility and makes your readers feel ill. To avoid the threat of a malpractice suit, you need to start exploring the innards of your sentences—stat!

Before you can do surgery on your writing, though, you need to brush up on your subject-verb anatomy. A singular subject agrees with a singular verb, and a plural subject agrees with a plural verb. A singular subject involves a single item or person: “the rolling gurney” or “a surgical patient.” A plural subject involves more than one item or person: “some badly written hospital signs” or “the shocked copy editors.”

Your subject-verb agreement is most likely fine when the subject is close to the verb, as it is here: “The rolling gurney is about to crash into the unwary sign writer!” The singular subject “gurney” pairs up with the singular verb “is.” I’m certain, though, that you sometimes commit a ghastly grammar goof when the subject is far from the verb. Be especially careful of compound subjects, which contain an “and.” Amnesiac writers forget about the first part of their subject, so they use the wrong verb. This was certainly the problem on Doctor Doofus’ phone system; the compound subject “patience and consideration” belongs with “are,” not “is.”

Now that you’re awake we can examine another reason you might be giving your readers an ulcer. The problem we’re dealing with here is stuff—and, mind you, “stuff” is a real medical term. This sneaky stuff distracts you into using the wrong verb. The troublemakers that come between your subject and verb include prepositional phrases (such as “in the operating room”) and “that,” “who” or “which” clauses. Let’s look back at our friend the hospital sign that read "The use of cell phones and pagers are prohibited." The prepositional phrase “of cell phones and pagers” is in the way. The subject of that sentence is “use,” which is singular, so the verb should be “is.” And that is that.

Have you been forgetting to get regular agreement checkups like our errant sign writers? I guess I’ll forgive you—if you promise to perform a mistake-ectomy immediately. It’s actually quite easy. Simply find your subject and circle just the word (or words) that form the subject—and ignore everything else. Then, underline the verb and check if subject and verb match. If they don’t, berate yourself for a few minutes and then fix the problem. Take this sentence: “Doctor Doofus, who needs a new phone message, and Nurse Nincompoop, his fiancée, are eloping tonight.” The subject is… what? Ah, yes, circle both “Doctor Doofus” and “Nurse Nincompoop”--the plural subjects. Forget about the erroneous phone message and the lucky fiancée. Next, underline “are eloping.” It’s a match! Plural subjects--plural verb.The wedding can commence, and no one will have a heart attack.

All these circles and underlines might seem tedious, but please mark up your pages until your subject-verb inflammatory disease is cured. Both you and your readers will feel much better if you examine your work thoroughly and get rid of careless errors. My surgeon certainly was thorough; he triple-checked that he didn’t leave any surgical instruments in me. Thanks, Doc. Your patience and consideration are much appreciated! You probably don’t have to check your work three times—once should be sufficient; twice if you write hospital signs for a living.

I hope you enjoyed my mixing it up a bit by bringing Bonnie Trenga in as a guest writer. This piece originally appeared in Writer's Digest, and if you enjoyed it, you can find more of Bonnie's work at http://sentencesleuth.blogspot.com. And, as I said, she is also the author of The Curious Case of the Misplaced Modifier, where she takes similarly fun approach to grammar and which you can buy from a link on quickanddirtytips.com.

Free Audiobook from Audible.com

Speaking of books, it's free book time again, compliments of Audible.com--the leading provider in spoken word entertainment. Audible has over 35,000 titles to choose from to be downloaded and played back anywhere--just like this podcast. I went through my library of Audible books tonight and was remembering how much I enjoyed a book called John Adams by David McCullough. There's a different book about John Adams on the best-seller list this week, but the book I listened to came out in 2001. Since you listen to this podcast, I know you like to learn, and I learned so much that I didn't know about John Adams from this book. His wife Abigail played a huge role in his life, and if you think politics can get ugly now, it was just as bad, if not worse, back then. I really think you'd enjoy this book, so log on to audible.com/grammar to get a FREE download of John Adams, the one by David McCullough, or an audiobook download of your choice when you sign up today. I shouldn't have to tell you this, but grammar is spelled with an a: g-r-a-m-m-A-r. Again, for your free audiobook, go to audible.com/grammar.

Questions and comments for me go to feedback@quickanddirtytips.com or the voicemail line at 206-338-GIRL. You can also read the full transcript of this podcast at www.quickanddirtytips.com, where you can leave comments and find the other great shows including Money Girl, The Mighty Mommy, and The Get-It-Done Guy.

That's all. Thanks for listening.