BizWritingTip reader: When is it ok to use a comma before “and”?
BizWritingTip response: Many people tell me that they have been told never to put a comma before “and.” However, as we all know, never say “never.”
When listing a series of ideas in a sentence, you separate the thoughts with commas. But when you come to the last point, should you add a comma as well as the word “and”? The answer is: “It depends.”
If the reader needs the comma for clarity, then add it. If the message is clear without the comma, then don’t use it.
Our plane landed at Winnipeg, Toronto and Montreal. (The reader easily understands that these are three separate locations.)
We need to focus on retaining our existing members, recruiting new members, and updating our website. (The comma before the “and” emphasizes that there are three distinct areas.)
We need to focus on retaining our existing members, recruiting new members and updating our website. (Because there is no comma before the “and,” the emphasis on three distinct areas is now reduced. You may even find a busy reader pays little attention to the middle point. Is this your goal?)
Note: Try to avoid writing sentences that require more than four pieces of punctuation. This means you can have three commas in a sentence. (The final period counts as the fourth piece.) If your sentence requires four commas, it means you are putting too many ideas in one sentence, and a busy reader will have trouble following your thoughts. You are probably better off with two sentences or a list.
No. You cannot break the no-more-than-four rule by removing all commas. Readers need their information chunked into easily digestible bites. This is the purpose of commas.