Commas around Appositives—When and Why?

commaWhen do you put commas around appositives? First, in case you’d appreciate the reminder, an appositive is a noun or noun phrase that renames the noun directly preceding it. How many appositives does the following sentence have?

My neighbor Aleks, a rock collector, likes malachite.

Two. The first appositive—the name, Aleks—renames the subject, neighbor. Assuming that other neighbors exist, the reader needs this name to make sense of the sentence. Grammarians call this kind of appositive “restrictive.” The word Aleks restricts the word neighbor—narrows it down to the neighbor we’re talking about. Because the appositive Aleks is restrictive, it takes no commas, as shown in this simplified example:

My neighbor Aleks likes malachite.

The noun phrase a rock collector serves as an appositive for the noun Aleks. If we remove this second appositive, a rock collector, from the sentence, we still know which neighbor we’re talking about. We don’t need to restrict, or narrow down, Aleks. Because the appositive a rock collector is nonrestrictive, it takes commas, as shown in this simplified example:

Aleks, a rock collector, likes malachite.

When you wonder whether to put commas around an appositive, imagine those commas as greased skids causing the appositive to lose its grip on the adjacent words and slide out of sight. Does the remaining sentence still make sense? If so, use those slippery commas. If not, don’t.


Now that you’ve read my explanation, above, I invite you to step back and notice the appositives throughout the explanation itself. To make that easy, I’ve pasted the same text below with the appositives and their precedent nouns bolded. In each case, notice the way the presence or absence of commas supports your reading experience.


When do you put commas around appositives? First, in case you’d appreciate the reminder, an appositive is a noun or noun phrase that renames the noun directly preceding it. How many appositives does the following sentence have?

My neighbor Aleks, a rock collector, likes malachite.

Two. The first appositive—the name, Aleks—renames the subject, neighbor. Assuming that other neighbors exist, the reader needs this name to make sense of the sentence. Grammarians call this kind of appositive “restrictive.” The word Aleks restricts the word neighbor—narrows it down to the neighbor we’re talking about. Because the appositive Aleks is restrictive, it takes no commas, as shown in this simplified example:

My neighbor Aleks likes malachite.

The noun phrase a rock collector serves as an appositive for the noun Aleks. If we remove this second appositive, a rock collector, from the sentence, we still know which neighbor we’re talking about. We don’t need to restrict, or narrow down, Aleks. Because the appositive a rock collector is nonrestrictive, it takes commas, as shown in this simplified example:

Aleks, a rock collector, likes malachite.

When you wonder whether to put commas around an appositive, imagine those commas as greased skids causing the appositive to lose its grip on the adjacent words and slide out of sight. Does the remaining sentence still make sense? If so, use those slippery commas. If not, don’t.


During your first readthrough—unless you read the way I do, one eye out for meaning and the other out for mechanics—you probably gave little thought to the bolded appositives or their punctuation. You didn’t need to. That’s the point. The commas did their work in the background. Like a well-trained butler, thoughtfully used punctuation serves the reader without calling attention to itself. Of-a that I’m a-positive.