If you pay close attention to written greetings, you’ll notice a difference in how people punctuate them. Some include a comma after the greeting word (Hi, Bob), while others skip it (Hi Bob). Sometimes it depends on the greeting word (Hi Kate but Hello, Kate), the register (Hello honey but Hello, Dr Smith), or things like mood and whim. So what are the rules for this erratic mark?
The comma in question is called the vocative comma, because these structures are in the vocative case. The word has the same Latin root as vocation and shares its sense of ‘calling’. The vocative comma is used in many more situations than just greetings: Yes, your honour. Good night, love. Thanks, buddy. Et tu, brute? Happy new year, everyone! Tell me more, Stan.
The purpose of the vocative comma is to separate the person or thing being directly addressed from the rest of the line. That means it doesn’t always precede the addressee – it can also follow them: Anne, look at this. Ladies and gentlemen, you’re all welcome. Guys, come over here. If the addressee appears in the middle of the line, commas are added either side: It is time, my friends, to make a decision. Would you agree, folks, that this is important?
In informal or unedited writing, the vocative comma is often skipped. If you’re emailing or texting a friend or family member, it may seem unduly fussy to you to include the comma after ‘Hi’. If you’re writing a formal letter, on the other hand, leaving out the vocative comma may seem too casual. In between these two poles there is much variation, which can depend on context, personal preference, and the writer’s awareness of the options.
Your choice may also be influenced by what the other person does. If they email you first with Hello, Name, you may feel you should reply in kind, even if you wouldn’t have used a comma otherwise. This relates to the idea of accommodation in linguistics and communication theory: adjusting our style of language to be more (or less) like our interlocutor.
Grammar sticklers tend to insist on using the vocative comma in all situations where it could apply, but it’s not essential in casual exchanges. That said, you may want to consider using it if you think it will matter to your reader. If you’re inclined to omit it, be alert to the possibility of ambiguity: I’m fighting John is altogether different from I’m fighting, John.
So what’s your preference, dear reader?