I know that a comma is necessary before a conjunction joining two independent clauses, like in the following examples:

John is tall, and Mary is fast.

The food is excellent, but the service is awful.

But what happens when there is a subordinate clause formed in turn by two independent clauses connected by a coordinating conjunction? Should there be a comma before the conjunction? I am referring to sentences like these:

She says that John is tall and Mary is fast.

I hate those restaurants where the food is excellent but the service is awful.

I am leaving the country so that the police cannot find me and I don't go to jail.

I tend to think there should be no comma in this kind of sentences, but I would appreciate if someone could confirm it. Assuming I am right, is that true independently of the length of the coordinate clauses?

1 Answer 1


Your instincts seem correct. The clauses that are independent in your first example are treated in the subsequent examples not as clauses, but as objects in a series.

She says [what]

She says A [John is tall] and B [Mary is fast]

The second example is even more clear. The type of restaurants that are hated must meet two criteria: excellent food AND awful service. The items are not really independent, even if they are expressed in separate clauses.

Note that treating these clauses as a series rather than as independent thoughts would lead to the use of commas if there were more than two concepts in the series

She said that John is tall, Mary is fast, and Peter is charming.

This follows the common approach of not separating two items in a series with a comma but using commas when there are three or more items.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.