Editing Tip of the Day: Verb Agreement

Hello, fellow writers in the editing trenches. Let's have a talk about noun-verb agreement.
Noun-verb agreement means that your subject noun of your sentence needs to agree, or match properly, with your verb. So if you use a first person singular noun, your verb needs to be in the first person singular form as well.
Examples: I ate the cookie.
They walked the dog.
Did you read the book?

Simple, right? Most of the time, we see problems with noun-verb agreement in more complicated sentences, like these:
They went to the store, shopped for groceries, and drove home.
She sang a song, skipping as she went.
Grabbing his coat, he said goodbye to his wife.
When there are multiple actions in a sentence, they each have to coordinate with their noun.

Things get even more complicated if you switch subjects partway through the sentence, and noun-verb agreement becomes extra important. Otherwise the reader can't tell who's doing what in the sentence. For example:
Jane sang a song, while the children danced wildly.

Here's a tricky format I've seen authors struggle with:
He listened to the music,  his feet tapping​, and smiled.
In this case, "he" is the subject of listened and smiled. "His feet" are the subject of tapping. Since I used a simple verb form for listen and smile, and a gerund (-ing) form for his feet, it should be pretty clear which verbs go with which nouns.

But what if I had written it as: He listened to the music, his feet tapping, and smiling. In that case, it suddenly sounds like his feet are smiling, since those verb forms match.

If I really wanted to use the gerund form of smile, I could clear up the confusing by changing the order so that smile comes before I change subject nouns: He listened to the music, smiling, his feet tapping. 

This works because a verb refers back to the most recent noun that agrees with it. So if you love to write long, complicated sentences (like I do!), always remember to make sure that your nouns and verbs are in agreement. Otherwise, you might end up with smiling feet.