Comma Before Or | Correct Use & Examples
Put a comma before “or” when it’s used to connect two independent clauses. A clause is independent if it contains a subject and verb and expresses a complete thought.
However, when “or” connects two verbs with one subject, it should not be preceded by a comma.
These rules also apply to using commas with the coordinating conjunctions “and” and “but.”
When to use a comma before or
You should put a comma before “or” when it connects two independent clauses (i.e., two clauses that contain separate subjects and verbs).
This is the case even if the subject of the second clause refers to the same subject as the first, or if the verbs in both clauses are the same.
Did Sorcha attend the party, or did she miss it?
In these instances, you can simplify your writing by omitting the second subject. You can also omit the second verb, if it’s identical to the verb in the first clause. Doing this eliminates the need for a comma.
Did Sorcha attend the party or miss it?
When “or” connects two short independent clauses that are closely related, the comma is usually considered optional.
You’re either in, or you’re out.
You should also put a comma before “or” when it’s preceded by something that’s usually set off by commas, like a nonrestrictive relative clause or a parenthetical expression.
You can pay with cash, of course, or with a credit card.
When not to use a comma before or
As a conjunction, “or” can be used to connect various words, like nouns, verbs, and adjectives. When “or” is used to connect two words like these, rather than two independent clauses, no comma is needed.
- Would you like tea, or coffee?
- Would you like tea or coffee?
- Should I bake a cake, or make cookies?
- Should I bake a cake or make cookies?
- I think we should paint the wall either white, or gray.
- I think we should paint the wall either white or gray.
However, it’s usually recommended to include a comma before “or” at the end of lists of three or more items. This is called the Oxford comma or serial comma.
When to use a comma after or
You should only include a comma after “or” when it is followed by an interrupter, (i.e., a parenthetical expression that adds emphasis or qualifies a statement). A comma should also appear after the interrupter.
You can take the day off or, I suppose, work from home.
- We can keep going. Or, we can turn back.
- We can keep going. Or we can turn back.
- We can keep going. Or, if you like, we can turn back.
Worksheet: Comma before “or”
Test your knowledge about when to use a comma before or after “or” with the worksheet below. Add commas wherever you think they are needed. You can then compare your work with the answers and explanations provided.
Frequently asked questions about commas before or after or
- How are independent clauses linked to other clauses?
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Independent clauses can be joined together using a semicolon (e.g., “I love my puppy Coco; she is so much fun”) or a comma and coordinating conjunction, like “and,” “but,” or “so” (e.g., “I wish I could play with Coco all day, but I have to work”).
Independent clauses can also be joined with dependent clauses to form complex and compound-complex sentences.
