Rule 1. Use a Comma with and, but, or, for, nor, so, yet to Separate Two Complete SentencesRule 2. Use a Comma to Separate a Long Introduction from the Rest of the SentenceRule 3. Use Commas to Separate Items in a SeriesRule 4. Use Commas—One Before and One After—to Separate an Interrupter from the Rest of the SentenceRule 4½. Use a Comma to Separate Elements That Could be Misunderstood If Read Together