Michael Eriksson
A Swede in Germany
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The idiot’s comma

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A truly absurd language error, and one disturbingly common, is what I think of as “the idiot’s comma”. For example:

The movie starred the actor, Brad Pitt.

This creates the impression that “the actor” is enough to uniquely identify someone or something, while “Brad Pitt” is an incidental fact, a disambiguation, an explanation, or some other type of apposition to the core information. In reality, however, Brad Pitt is just one of many, many actors and the sentence should correctly speak of “Brad Pitt, the actor” (identifying information followed by secondary information) or “the actor Brad Pitt” (compounded identifying information).


Arguably, the issue of order is more important than that of punctuation, making “the idiot’s comma” potentially misleading. The phrase has been stuck in my head for years, however, and finding a different name for the purposes of this text would be awkward.

Mentioning that specifically Brad Pitt is an actor might seem redundant—and the more so in the context of a movie cast. With other names and in other contexts, this need not be the case. Consider e.g. John Williams, the actor, who might be confused with John Williams, the composer, in a movie context. Conceivably, it would even make sense to give the former as “John Williams, the British actor”. The latter, in turn, might well be confused with John Williams, the guitarist, in a musical context. (Not to mention the countless others of the same name.)

There are other situations where a reversal following the pattern “the actor, Brad Pitt” can be justified, because the first part suffices for identification, be it in general or in the context at hand. For instance, “the first U.S. President” uniquely identifies someone and a formulation like “the first U.S. President, George Washington” can be perfectly acceptable.


The choice of order would depend on what matters more for the topic at hand. A history of the U.S. might mention that “the first U.S. President, George Washington, was in office 1789–1797”, while a biography of Martha Washington more naturally speaks of her being married to “George Washington, the first U.S. President”.

Moreover, issues like timing might play in, e.g. in that Martha Washington did not marry the first U.S. President, even if her husband later became the first U.S. President. Here a formulation like “she married George Washington, later first U.S. President” might be appropriate. The pedantically inclined might, depending on what exact meanings are implied, even argue that a claim like “the first U.S. President, George Washington, was elected in 1789” would be incorrect and “George Washington, the first U.S. President, was elected in 1789” preferable. (I am uncertain whether 1788 or 1789 is the better choice of year, but the exact year is beside the point.)

Even in such cases, however, care is needed, as the uniqueness might be strongly context dependent and/or require knowledge not present in the average reader. For instance, a newspaper published today (2024-01-03) that discusses current U.S. politics might be justified in a formulation like “the President, Joe Biden”, but not so if we change the year to 2014 or 2034 (presumably), the country to Germany, or the context to some non-political entity having a president.

An alternative is the use of formulations like “actor Brad Pitt” (note absence of “the”). While I have no strong personal opinion, I have seen such formulations condemned by others, especially when somewhat lengthier (“award-winning actor Brad Pitt”), and some caution might be needed. (In the special case of actual titles, e.g. “President”, use should be uncontroversial.)

Note on examples and use of other formulations

The alternatives chosen above are intended to fit the original pattern. In many actual situations, entirely different formulations might be better, and the above is not a recommendation to follow to a certain pattern. The point is that the idiot’s comma be avoided, should the pattern be followed.

Excursion on the reason and commas-within-quotes

The reason for the commonality is likely that there is some guide somewhere that actually recommends this idiocy. I have no recollection of ever seeing such a recommendation, but the choice is so obviously and manifestly wrong that it is hard to see how so many could have independently arrived at this error.

A potentially similar case is the idiocy of putting punctuation within quote marks, even when they logically belong to the surrounding sentence, as with:

A famous quote is “to be or not to be,” said the teacher.

This deviation from the obvious choice has a historical reason, however, in that it had some advantage in the days of manual type setting—and the recommendation is still often found in style guides.

(Of course, these fail to consider that the days of manual typesetting are long gone and that the continued use of such artificial and illogical rules cannot be justified in new material. I might go so far as to claim that a good author, even “back then”, should have put the punctuation in its proper place and let the typesetter make the modification, if and when it was necessary. That, however, is a different question.)