Punctuation Tips: Commas After Introductory Phrases

You can use introductory phrases and words to frame or modify a sentence in your writing. But when do you need a comma after an introductory element? In this post, we offer some punctuation advice and look at when to use a comma after introductory phrases, clauses, and words.

Commas After Introductory Phrases

Let’s start in broad terms. By “introductory phrase,” we mean any group of words used to frame or modify a sentence that isn’t a complete clause.

There are no strict rules about when to add a comma after an introductory phrase. However, common guidelines for when to use a comma include:

• When an introductory phrase is more than four words.
• If you want to imply a distinct pause before the main sentence.
• To prevent ambiguity or confusion.

In the case of longer introductory phrases, the comma helps ensure the sentence reads smoothly. For instance:

After thinking long and hard, Megan decided to confront Beth.

You can also include one for shorter phrases, but this is optional:

By Tuesday I was ready for the weekend.

By Tuesday, I was ready for the weekend.

It’s worth checking your style guide if you’re using one, though, as some will specify how many words to use before you should add a comma.

Introductory Dependent Clauses

You will also need to add a comma after the introduction when a sentence begins with a dependent clause. This is a clause that starts with a subordinate conjunction, like “while” or “before”:

While we were playing tennis, our friends had a picnic.

Before I started this job, I was a student.

However, you only usually need to use a comma when a dependent clause introduces a sentence. If we flipped the sentences above so the main clauses came first, for instance, we wouldn’t use commas:

Our friends had a picnic while we were playing tennis.

I was a student before I started this job.

So you only need a comma when the dependent clause comes first!

Introductory Words (Sentence Adverbs)

Sentence adverbs are words that modify a full sentence, not just part of it. And if you use a sentence adverb to introduce a sentence, you will need to use a comma after the introductory word.

Some of the most common sentence adverbs are adverbial conjunctions, such as “however,” “furthermore,” “meanwhile,” and “therefore,” which let us connect sentences to improve the flow of writing:

Meanwhile, Tony was in the kitchen washing the dishes.

However, there is no evidence eating oranges improves life expectancy.

Likewise, we can use an adverb to frame a sentence with an opinion or attitude. In this case, the introductory word tells us how the reader feels about the rest of the sentence. For instance:

Ideally, we will move into the new house next month.

Thankfully, Thomas wasn’t hurt in the incident.

Here, “ideally” and “thankfully” tell us the attitude of the author about the thing expressed in the rest of the relevant sentence. If you’re using a word to introduce a sentence like this, always include a comma.

Summary: Commas After Introductory Elements

You can often use a comma to separate an introductory element from the rest of a sentence. Key cases where you’ll want to do this include:

• After longer introductory phrases (e.g., four words or more).
• To imply a pause or prevent confusion.
• When a sentence starts with a dependent clause.
• When using a single adverb to frame a whole sentence.

If you’d like to be sure you’ve used commas correctly, meanwhile, proofreading is the answer! Try our services for free by uploading a 500-word sample document today and find out how we can help.