A large senior health center in my neighborhood recently hoisted over its main entrance a banner that reads: Thank you team, for fulfilling our mission. Many of us, unfortunately, were first taught to punctuate by following our breath: put a comma where you breathe, we were told earnestly and often. This is excellent advice at the higher reaches of rhetorical design, but not so good for organizing an ordinary sentence according to a handful of basic rules meant to get the job done easily and accurately. It is also, most likely, what accounts for the incorrect punctuation proudly displayed here.
The construction at issue is called direct address, and there is a very simple and straightforward and invincible rule that pertains to it: nouns in direct address are set off by commas. The sentence on the banner contains two nouns, team and mission, and it is the team, not the mission, that the writer behind the banner is speaking directly to. Applying the rule, we have the quick and easy and accurate correction: Thank you, team, for fulfilling our mission.
Now the rule as I have stated it assumes we know that an English sentence never begins with a comma, and that a period never follows a comma. So if, in a somewhat ham-handed effort to capture the addressee’s attention hard and fast, the sentence had begun with the word team, then using only one comma, the first of the required pair, would have still accorded with the rule: Team, thank you for fulfilling our mission. Or had team appeared at the end of the sentence (a better because more natural arrangement), only the latter of the pair of commas would have been in order: Thank you for fulfilling our mission, team.
In fact, where the writer did place the term of direct address—neither in first position nor last, but somewhere amidst the clause—is the arrangement best suited to the occasion. This kind of design is called a postpositive construction, postpositive meaning in its derivation nothing more recondite than placed after, that is, placed somewhere after the first position of a clause. And in a postpositive construction, the punctuation rule is applied unconditionally: nouns in direct address are set off by commas.
Beyond its workaday application, attending to this rule about punctuating nouns in direct address can keep our attention on the emotional effects our sentences provoke, something conscientious writers are always aware of. More sensitive now to where such a noun is placed, you can almost feel the syrupy and mawkish tone when the noun is in the first position: Team, thank you for fulfilling our mission. This arrangement often appears in sales letters and business correspondence, and the effect is almost always a false, even cloying, chumminess. That effect is erased when the word moves to the final position, but what does arise there is an earnestness inappropriate to the circumstance, something more akin to a barker hustling a crowd: Thank you for fulfilling our mission, team!
Punctuation, then, has a material effect on both the accuracy and impression of our sentences. Rules can be broken, of course, but broken knowingly and to an identifiable purpose otherwise unachievable. That standard is difficult to meet in everyday sentences like the one we have been considering here.