Note: Most people would probably agree that commas are the most confusing punctuation marks because there are so many rules dictating when and how they should be used. I will not attempt to list all the comma rules on this page (there are some excellent sites listed on the Resources page that explain all the rules of comma usage); instead–in keeping with the theme of this site–I will highlight a few of the errors that I’ve observed to be the most common.
I often receive e-mails that begin with the following greeting: “Hi Rachel.” Although this is certainly a friendly way to begin a letter, it violates one of the many comma rules: Always use a comma when directly addressing someone/something, regardless of whether the direct address is at the beginning or end of the sentence. If the direct address is in the middle of a sentence, use a pair of commas to set off the direct address.
Note the placement of commas in the example sentences below:
Example 1: Ladies and gentlemen, may I have your attention? (Direct address at beginning of sentence)
Example 2: It was a pleasure to meet you, Sir. (Direct address at end of sentence)
Example 3: Thank you, my fellow grammarians, for remembering to use correct English. (Direct address in middle of sentence)
So, you see, the salutation “Hi Rachel” should be “Hi, Rachel.” A comma is needed between Hi and Rachel because it is a direct address.
Keep sending the e-mails my way, but remember that I’ll be on the lookout for any missing commas.