comma before 'while' [conjunction]: Times Square is..., while Forum


Senior Member
English - United States
Is a comma before "while" correct here?:

--Times Square in New York City is the modern center of the world’s largest city, while Rome’s Forum Square held this title in earlier times.

  • It's not necessary and I probably wouldn't use it. I'm not sure if I would consider it wrong though.
    It sounds fine to me, but it's probably not necessary — although the claim that New York City is the world's largest city is ludicrous.

    I've had English professors and teachers that have taught commas with very strict rules, but then I've also had ones who have taught that it's mostly just what sounds right. Ultimately, in my opinion the comma is not wrong, but I wouldn't say it's right.
    Well, I know that when "while" is used meaning "at the same time as," a preceding comma is almost always incorrect. However, when "while" is used like "whereas," it conveys a sense of contrast that seems to warrant a comma more. Purdue's online writing lab explains:

    However, don't put a comma after the main clause when a dependent (subordinate) clause follows it (except for cases of extreme contrast).

    Incorrect: She was late for class, because her alarm clock was broken.
    Incorrect: The cat scratched at the door, while I was eating.
    Correct: She was still quite upset, although she had won the Oscar. (This comma use is correct because it is an example of extreme contrast)

    By the way, this is in the context of the 1940s, during which New York City had the largest population.
    The current view is to use no commas if the sentence meaning is clear. For a guideline where your sentence structure would likely be misunderstood a comma is necessary.