Woman sitting at desk reading a piece of paper

If you’re like me, it drives you a little bonkers when you try to read something and it doesn’t make sense because a comma was/wasn’t used when it should’ve been — especially the Oxford or series comma. So, here it is! A guide to basic comma usage.

When to Use a Comma & When Not to Use a Comma

When you combine two complete sentences into one with two subjects and two verbs, use a comma.

  • Susie went to the post office, and it was closed.
  • John is a poet, and Sharon is a biographer.

The Oxford comma or series comma — use it! Nothing can change the meaning of a sentence like when this is missing.

  • At the concert, there were young people, middle-aged people and dogs.
    • Are the dogs middle-aged or just the people?
  • At the concert, there were young people, middle-aged people, and dogs. (Correct)

Sometimes two things are relational and there’s no need for a comma.

  • His sandwich was made of white bread, mayonnaise, and peanut butter and jelly.

The ampersand — comma or no comma? No comma!

  • Books, Candles & Essential Oils

Introductory comma: If the sentence is short, there’s no need for an introductory comma unless the meaning could be confused.

  • On Friday I went to lunch with a friend. (Correct)
  • In April Sue went to the museum to give a presentation. (Incorrect — is her name April Sue? Do you trip when reading this sentence?)
  • In April, Sue went to the museum to give a presentation.

If it’s a longer intro or a place where you would naturally pause, the comma helps with ease of reading.

  • While at lunch with a friend, we decided to see a matinee.
  • While at lunch, a friend and I decided to see a matinee.

The bottom line is this: if a sentence is confusing when you’re writing it, it probably needs a comma or to be broken into two sentences.

The beautiful thing about the English language is that there are some exceptions to every rule, however, comma usage can make or break a sentence and leave your readers stumbling along thinking about what they’re reading instead of enjoying the meaning.

Happy writing my writing warriors!


Have questions about comma usage or comments? I’d love to hear them!