Comma after “So”? (AP vs. Chicago Style)

Knowing how to use commas correctly in English can be tricky, and people are often confused by whether to add one after “so.” This page looks at the circumstances when you should use a comma after “so” and when you shouldn’t.

Comma after “So”?

Mostly, you don’t need a comma after “so” when it is a conjunction meaning “therefore.” In certain instances, you may include a comma if it is “necessary” for the reader to pause or separate “so” from other words.

comma after so

The question of if there is a comma after so is a common one that often causes confusion. The word “so” can be an adverb or conjunction, and when it is a conjunction, there is hardly ever a comma after the word, both when it starts a sentence or when it is in the middle.

However, there are occasions when you want the reader to pause for a meaningful turning point in the text or when joining “so” with the second word in the sentence would be confusing.

Here are some examples of when to use a comma after “so” and when not to: Please note that in the ones without the comma, it is often best to write these types of sentences as one sentence and use a comma before the word “so” rather than a period.

Without comma:

  • We asked him to leave, so he slowly stood and walked out of the room.
  • He never listens to what I say. So now he thinks I am rude and arrogant.
  • Nobody heard the instructions. So nobody knew what to do.

With comma:

  • So, long after he had said he was leaving, he was still there.
  • So, much was said about the problem, but nobody had a solution.
  • So, after thinking about it long and hard, he decided not to go.

Comma after “So” – AP Style

It is not necessary to put a comma after the word “so” in AP Style unless the “so” marks a significant turning point in the discourse or if the terms following it would confuse the reader when combined with the word “so.”

However, most of the time, it is not necessary to include a comma after “so” in AP Style:

Here are some examples with and without commas:

Without comma:

  • We didn’t study for the exam, so we all failed badly.
  • So that he wouldn’t feel left out, we invited him to the party.
  • He was shouting, and nobody could hear the class. So we eventually asked him to leave.
  • So nobody would feel left out, we invited the whole department.
  • So far, we haven’t seen anyone else we know at this conference.

With comma:

  • We drove for hours without any clue where we were going. So, long after we had set off, we eventually arrived.
  • We didn’t know what day the exam was supposed to be. So, many people panicked because they thought they had missed it.

Comma after “So” – Chicago Style

In Chicago Style, it is unnecessary to add commas after the word “so” unless you need to do so for stylistic reasons. The stylistic reasons will be present if the words after “so” sound weird if there is no pause or if there is a drastic change or shift in the discourse and you want the reader to pause.

Most examples from literature and formal writing do not include a comma after the word “so”, and having a comma after it is a habit that only gained widespread popularity in the 21st century.

Here are some sentences with and without commas in Chicago Style:

Without comma:

  • He didn’t ask me if I could help, so I didn’t offer.
  • His parents asked him to get a job or move out. So he knew he had to do something fast or he would be homeless.
  • We haven’t seen him so far today.
  • So far, we have travelled over 100 miles.

With comma:

  • He never studied the material for the class. So, many times he failed the assessments.
  • The teacher was not clear with the instructions. So, few of us knew what to do.

Comma after “So” – APA Style

APA does not differ from the other styles; you only need to use a comma after “so” on two occasions.

The first is when there is a dramatic shift in the discourse for which you want the reader to pause. Whilst the second is when the words following “so” do not combine well with it because it takes a new meaning when combined. As is the case with words such as “many” and “much.”

Here are some examples of “so” in a sentence with and without commas:

Without comma:

  • So far, we have done 3 out of 4 exercises.
  • I haven’t done much so far today. 
  • You have all worked really hard this semester. So I know you will do well on the exam.

With comma:

  • We didn’t know what we were doing. So, much of our time in the meeting was wasted.
  • He didn’t specify what time the meal started. So, nobody knew what time they were supposed to arrive.

Comma after “So” – MLA Style

As with the other styles, in MLA, it is not standard to include a comma after the word “so”. You should only include a comma if you want the reader to pause for a shift in the discourse or when the terms following “so” do not sound right when combined with it.

Most examples in literature do not use a comma after “so”, and its inclusion is a habit that started to gain traction in the 21st century.

Here are some examples of “so” with and without commas:

Without comma:

  • There was nothing you could have done. So you shouldn’t blame yourself.
  • Nobody had invited her to the event. So she decided to stay at home all day.

With comma:

  • So, long after he had asked the original question, he got an answer.
  • He was away for weeks. So, many people asked him where he had been.

Final Thoughts

The word “so” is usually not followed by commas. The two occasions to use a comma are when the terms after “so” do not combine well or when there is a dramatic shift in the text for which you want the reader to pause.