BizWritingTip Reader: “I have a question for you – when is it OK to use commas before ‘and.’ I find this to be a very subjective question and am looking for some clarification.”
BizWritingTip Response: There are several rules surrounding “and.” And that’s probably why the issue can be confusing. It all depends on how you are using the word. I will explain how to punctuate “and” when you are using it in a compound sentence in this BizWritingTip. I’ll show you how to deal with it when you are using it in a series of ideas in the next issue.
A compound sentence consists of two independent clauses joined by the co-ordinating conjunctions and, but, or or nor. Place a comma before the conjunction.
The report was lengthy, and I did not have a chance to read the entire document. (There is a comma before “and” because it is joining two separate thoughts. I could have also written: “The report was lengthy. I did not have a chance to read the entire document.”)
Do you plan to attend the conference, and will you attend the final dinner? (This is also a compound sentence. There are two subjects: you. That’s why there is a comma before “and.”)
Note: If your two thoughts are quite short, you can omit the comma. For example: The food is good and the service is excellent.
However, sometimes you might use “and” in a sentence that does not contain two separate thoughts. It just has one subject and two predicates (verbs). In this case, do not place a comma before the conjunction “and.”
The report is lengthy and has a number of spelling errors. (There is no comma before the “and” because there is only one subject: the report.)
Do you plan to attend the conference and to stay for the dinner this year? (There are two predicates, plan to attend and to stay, but only one subject, you. Therefore, don’t put a comma before “and.”)
At this point, you may be saying to yourself: “Why is this important? Does it really matter?” The answer is yes. It does matter. By putting in the comma, you are breaking your thoughts into sound bites and making it easier for the reader to follow your reasoning.