Introduction to Commas Part 2: Clauses

Now that you understand when and how to use a comma with coordinating conjunctions, it’s time to learn when to use a comma outside of just connecting to independent clauses. A comma can also be used for a variety of clauses like adverbial, nonessential, introductory, and more.

Introductory Clauses

Possibly the most accessible and most familiar of the clauses, an introductory comma is used when a clause introduces a word or phrase that provides extra information before the main clause of a sentence. Furthermore, it will usually provide information on the who, what, when, where, why, or how of a sentence (also called the Five Ws and H). An easy example would be: “In the summer, you need to remember to stay hydrated.” The introductory clause “In the summer” answers the when of our Five Ws and H, so it's offset with a comma.

While most of your writing may only have one introductory clause, it is also possible to have two introductory clauses, and both of these clauses would be offset with commas. An example would be: “In the summer, because of the heat, you need to remember to stay hydrated.” Both “in the summer” and “because of the heat” provide information on one of the Five Ws, so they are offset with commas.

Adverbial Clauses

Adverbial clauses, sometimes called subordinate clauses, provide additional information in the sentence or present a cause-and-effect relationship between the adverb clause and the main clause. Just like an introductory clause, an adverbial clause will answer one of the Five Ws and H. Adverbial clauses will also begin with a preposition or a subordinating conjunction.

Here is a list of the most common subordinating conjunctions: after, although, as, as if, because, before, even if, even though, if, if only, rather than, regardless, in order to, since, though, unless, until, whatever, when, whenever, whether, while, where, whereas, wherever.

Adverbial clauses at the beginning of a sentence act the same as an introductory clause and have a comma at the end of the clause. For example: “When you read this blog, you will learn information on comma usage.”

When an adverbial clause is in the middle of a sentence, both sides are offset with a comma. An example of this would be: “This blog, when you are reading it, will give you information on comma usage.”

Finally, adverbial clauses at the end of a sentence are not offset by a comma. For example: “This blog will give you information on comma usage when you read it.”

Nonessential Clauses

The final clause in this blog is sometimes the hardest to master since it can be hard to tell when information is nonessential. To test this, read the sentence both with and without the clause in question, and if the sentence makes sense without the clause, it’s not essential and is offset by commas; furthermore, words that end in “-ing” are often indicators of nonessential clauses as well. For example, “Phones, like the iPhone and Samsung Galaxy, have kept us in touch.” In this example, what matters is that “phones” is the noun and that they have allowed us to stay in touch, but the specific example of iPhone and Samsung Galaxy does not change the meaning as phones other than those can still apply to the sentence. 

However, sometimes the information is needed, and in that case, the information should NOT be offset by commas. An example of this would be: “Musicians like Paul McCartney have had great success both in a band and running solo.” For the above sentence, the inclusion of Paul McCartney is important as not all musicians have been in group and solo projects, nor have they all had great success if so. If you were to offset his name, the sentence would no longer mean that only certain musicians have had that happen but instead that all musicians share that experience.

Final Thoughts

The rules for using a comma when, where, and why are tough to master; even the best writers will offset a clause they thought was nonessential just to catch that it was needed, but the difference is being able to understand why and catching it before others are given your work. This is only the second of our comma blogs with more to come as we cover even more rules for this little punctuation mark.