Introductory phrases set the stage for the rest of your sentence, giving the reader valuable information about what is happening and why. There are several different types of introductory phrases, and there are specific rules for using these correctly. Learn when and where to use a comma after an introductory phrase and how to make your writing stand out with just the right words.
Before you learn how to correctly use and punctuate an introductory phrase, you need to have a clear understanding of what one is and why you would use it in a sentence. Simply put, an introductory phrase is a group of words that comes before the main clause in a sentence. It helps the reader understand more about the main clause.
An introductory phrase is not a complete clause; it does not have a subject and a verb of its own. It may have a subject or a verb, but it can’t have both. If it does, it’s called an introductory clause.
You can see how this works in this introductory phrase example:
Galloping quickly, the horse reached the other side of the pasture in less than a minute.
In contrast, this introductory clause example includes both a subject and a verb:
Because the horse was galloping quickly, he reached the other side of the pasture in less than a minute.
There are five common types of introductory phrases, and it’s important to understand how to use each one correctly. Each type serves a distinct purpose within the sentence.
In an introductory prepositional phrase, the sentence starts with a preposition and a few words that follow it. The prepositional phrase adds information to the main clause, often about a location or timing.
To use it properly, you need to use a comma after the introductory prepositional phrase to set it apart from the rest of the sentence if the phrase is longer than four words. You can see the proper punctuation in these examples:
- After the severe spring thunderstorm, the sky turned gold.
- In the very beginning of the story, a boy meets a stray dog.
- Along the way to my friend’s house, I saw several lilac bushes in bloom.
- Opening the door to my friend, I discovered that she was not alone.
If an introductory prepositional phrase is made up of fewer than five words and does not require a pause, the comma is optional. It is correct to use a comma and also correct to leave it out, as you can see in the example below:
- Correct: On average 40% of students take driver’s education at the high school.
- Correct: On average, 40% of students take driver’s education at the high school.
Using an introductory infinitive phrase also provides information to the reader, often about why something is happening. These phrases also provide location and other helpful information. An infinitive phrase begins with the word “to” and includes a verb. It may also include a direct object of the verb.
You should always use a comma after an introductory infinitive phrase, as you can see in these examples:
- To get to the store, turn left at Oak Street.
- To write a great essay, start with a good outline.
- To run the program, hit the “Start” button.
- To make biscuits, I use my grandmother’s recipe.
A participial phrase is another form of verb phrase. Like an infinitive phrase, it may have a direct object. It sets the stage for the main clause, allowing the reader to understand the context of what is happening.
Like an infinitive phrase, always set this introductory phrase off with a comma:
- Having finished his lunch, Sam went back to working on his art project.
- Running quickly, the boy caught up with the dog.
- Opening her eyes, she saw early morning light peeking through the curtains.
- Pouring the water on the plant, Carol admired the flowers just beginning to open.
An absolute phrase also adds information to the main clause, providing context for the reader to interpret the rest of the sentence. This type of introductory phrase offers a little more detail about the way in which something is happening or the reason for which it is happening.
An introductory absolute phrase requires a comma to set it off from the main clause, as you can see in these examples:
- Completely oblivious to the rain, the children continued to play outside.
- Though the flowers were fading, their perfume remained strong.
- Voice wavering, the child begged to be allowed to stay up late.
- Their arms around each other, they bowed their heads and walked on against the wind.
An appositive phrase offers an alternative description of a noun in the sentence. You can use this as an introductory phrase, giving the reader more information about the subject of the sentence or another noun.
When you start with an appositive phrase, you often need to use a comma after it. If the phrase is a nice addition to the sentence but is not necessary for clarity, you should use a comma:
- An insightful reader, Aaron offered a fantastic interpretation of the text the class was studying.
- A fine mouser, my cat caught every rodent that dared to come in the house.
- A confection of pink frosting and sprinkles, Cara’s birthday cake was a sign to behold.
- A jaw-dropping display of light and sound, the fireworks amazed all who were lucky enough to see them.
However, if the introductory appositive phrase is necessary to the sentence, you should not use a comma. Consider whether the phrase adds important clarifying information about the subject. Sometimes, these introductory phrases start with “the” instead of “a” or “an.” If the phrase does provide important clarifying information, don’t use a comma. These examples can clear up any confusion:
- The award-winning author Judy Blume came to speak at our school.
- The math teacher Mr. Cody was the one to administer the standardized test.
- The engineering manager Mr. Carrington led the meeting.
- The English class Introduction to Romantic Poetry was my favorite.
In general, it’s usually correct to use a comma after an introductory phrase. This is because you pause after the introductory phrase when you say the sentence aloud. However, like all aspects of the English language, there are a few exceptions. Learn more about comma usage to become a confident writer.