JS Tip 512: The Introductory Comma

We’re still discussing commas.

And, yes, we’ve done this before.  

Principle Three: Use a comma to separate an introductory passage from the main part of the sentence: 

Three days after we completed the project, a storm wiped out the access roads.

The introductory passage: “Three days after we completed the project.” 

The main part of the sentence: “A storm wiped out the access roads.” 

Setting off the introductory passage with a comma lets your reader know the main subject and the main verb of the sentence are still coming. 

Introductory passages come in three sizes: short, medium, and long. (Duh.)

No matter their size, they cannot stand alone because they introduce—they’re linked to, they’re connected to—the main subject and verb.

Introductory passages can be short (one word):

First, we did a weather study.

Medium (two, three, or four words):

In that study, we learned the area hadn’t had a major storm in five years.

Or long (more than four words): 

Despite what we had learned, the storm surprised us.

Some sources suggest dropping the comma when the introductory passage is short. We say bologna. (Baloney.) 

Let us know your questions. Seriously. We love this stuff.