Commas, commas, commas—who cares about commas? You should. They enable you to help your readers understand your meaning. They give you control over where your readers pause and divide sentences. And they can make the difference between an unclear sentence and a clear one. But commas have so many different uses that it’s easy to become confused about where to place them. Here, I’ll address the comma splice and compound predicate conundrums.

The Comma SpliceTo comma, or not to comma . . . that is the question.

Consider the following: “Revising your writing is crucial, thorough editing makes for a pleasant read.” This is a comma splice, which is something you usually want to avoid in your writing. Two complete sentences have been joined, or “spliced,” together with a comma. (Note, though, that a comma splice isn’t always wrong. It’s fine to use commas to “splice” together sentences if your sentences are short and parallel each other. “I wrote, I revised, I published.”)

So how can you deal with problematic comma splices?

One option is to substitute a period for the comma, transforming the statement into the two complete sentences already there. “Revising your writing is crucial. Thorough editing makes for a pleasant read.” If your two sentences are closely related, you could use a semicolon instead.

Alternatively, you could rework one of the independent clauses into a dependent clause to avoid a comma splice. “Because thorough editing makes for a pleasant read, revising your writing is crucial.”

Another solution is to include a suitable conjunction after the comma, such as “and,” “but,” “or,” “yet,” “since,” or “so.” “Revising your writing is crucial, and thorough editing makes for a pleasant read.” A comma isn’t necessary if you have a conjunction joining two independent clauses that are short and closely related. “Jane writes and John critiques.”

The Compound Predicate

If you opt to solve your comma issues by inserting a conjunction, check that you continue to have complete sentences on each side of the comma or you may have a compound predicate problem on your hands. “Jane writes for at least three hours a day, and she avoids revising for as long as she can,” not “Jane writes for at least three hours a day, and avoids revising for as long as she can.” The latter example has a compound predicate, with the verbs “writes” and “avoids” each referring to the subject “Jane.”

So, how do you correct a compound predicate problem?

It’s simple. When there is no subject in the second part of the sentence, no comma is needed before the conjunction. “Jane writes for at least three hours a day and avoids revising for as long as she can.” However, some style manuals recommend including a comma in sentences like this (especially when the conjunction”but” is used) if it is required for clarity. “Jane received a call from the agent who agreed to represent her, and passed out.” Without the comma, readers don’t know who passed out, Jane or the agent.

What kind of comma trauma do you suffer from? Please leave a comment!