Rule 1: When starting a sentence with “so,” you should use a comma after to indicate a “shifting point” in the text.
A “shifting point” is when the course of the message changes drastically.
For example, the shift between describing a situation and then stating the result of that situation.
- Correct: You have all done incredibly well. So, I am giving you all a pay rise.
- Incorrect: You have all done incredibly well. So I am giving you all a pay rise.
Rule 2: When you put the word “so” before a non-essential clause, you need to use a comma.
- Correct: And so, going against his parent’s wishes, he went out with his friends.
- Incorrect: And so going against his parent’s wishes, he went out anyway.
Rule 3: Do not use a comma when “so” means “so that” and there is a logical continuation in the sentence.
- Correct: He studied French so his Paris trip would be easier.
- Incorrect: He studied French so, his Paris trip would be easier.
Rule 4: When using “so” as a conjunction to separate two clauses, you should not use a comma afterward.
Although you will often see a comma before “so.”
- Correct: I couldn’t find my phone this morning, so I left without it.
- Incorrect: I couldn’t find my phone this morning, so, I left without it.
If you want to learn more about how to use commas with “so,” you should continue reading. We’ve included helpful example sentences to clear out any doubts you may have.
When to Use a Comma After “So”
When you need to decide when to use a comma after “so,” you should refer to Rule 1 and Rule 2.
Rule 1: Use a comma after “so” when it appears at the start of a sentence, and the words after it mark a “change” in the theme.
This “change” is often the result, consequence, or solution to what was stated in the sentence before “so.”
- It had been raining all night. So, when he tried to leave the house, the roads were flooded.
- We have not been doing well this year. So, I am announcing a new strategy to increase sales.
The term “so far” means “up to now.” When “so far” appears at the start of the sentence, the comma goes after “far” if there is a theme shift in the discourse.
- We have been working on the project for a week. So far, we have done about half.
Rule 2: Use a comma after “so” when it comes before a non-essential clause in a sentence.
A non-essential clause means that if you remove it from the sentence, it still makes sense.
- So, when you finish university, what do you plan to do?
- He had been at work all day. So, against his better judgment, he went out with his friends.
However, one exception is when “so” forms part of the non-essential clause; you should not put a comma.
- The captain of the team, so exhausted after giving his all, seemed devastated that they had lost.
- The man, so dehydrated he could barely open his mouth, begged for water.
When to Avoid a Comma After “So”
Rules 3 and 4 explain when you shouldn’t use a comma after “so.”
Rule 3: You shouldn’t use a comma after “so” when you use it to mean “so that.”
Furthermore, the term “so that” implies a logical continuation. Therefore, removing the word “that” means the same thing and does not require a comma.
- He sold his old car so he could buy a new one.
- She left earlier than usual so that she could beat the rush hour traffic.
Rule 4: Do not use a comma after “so” when it separates two clauses and operates as a conjunction.
It can be used to separate independent clauses, for example:
- She felt dizzy all day, so she went to the doctor.
- Jenny loves cold weather, so she is moving to Canada.
It can also separate an independent clause from a dependent clause:
- I didn’t leave for work early enough, so I arrived later than usual.
- I saw that Coldplay is playing a concert next month, so I will get us tickets for it.
Conclusion
You should use a comma when “so” starts a sentence, and the part that follows is a “drastic shift” in the topic. Also, when “so” comes before a non-essential clause, you should use a comma. Don’t use a comma when “so” connects two clauses or when it means “so that.”