comma before 'as' [conjunction]: burst forth, as he watched the


When deciding whether or not to put a comma before a phrase beginning with the word "as," does one need to consider rules of grammar? And which ones? For instance, whether or not the phrase is restrictive.

Here's an example of the kind of sentence I struggle with.:

"Peals of delighted laughter burst forth, and tears formed at the corners of his eyes as he watched the children fight."

Do I need a comma before the phrase "as he watched..."? If someone could explain this question or direct me to somewhere that could answer my question, I would appreciate it. thanks.
  • As [in the sense of 'when'] introduces a lesser clause, thus a comma is usual. A test might be to take as and the following clause and move it to the beginning of the sentence. Does it still make sense? If so, then a comma is good.

    That said, a short clause following as may not require a comma - "Tears formed at the corners of his eyes as he watched." or "Lock the door as soon as I go."

    If there is a rule, then it is to help the reader separate longish clauses.

    On the other hand, I wouldn't put a comma after "forth" because and is a coordinating conjunction and the subject is unchanged.
    Commas are used as needed, for the purpose of letting the reader pause or to prevent reader confusion. It's more often a judgment call than a matter of "rules". I agree with your use of the comma after "forth", and I agree that none is needed before "as".
    My preferences are, from best to worst:
    1. Use both commas.
    2. Use a comma only before "as".
    3. Use no commas.
    4. Use a comma only after "forth".

    If you have a comma only after "forth", as you do, then the first impression I form is that two events occurred: first the peals of laughter from somewhere or someone, and second the fighting which brought tears to his eyes. This impression is quickly discarded in favor of the more natural interpretation, but nevertheless involves my brain in unnecessary work.

    If you omit the commas altogether, then there is no risk of misinterpretation, but still I have to work harder to untangle the sentence. I'm grateful to any writer who conveys his meaning to me with the least effort on my part, and if he does a first-draft parse of the sentence for me then so much the better.
    A lot of my knowledge is sketchy and limited to high school grammar. Would most of you suggest a comma after "forth"? Isn't the comma connecting two independent clauses? Or does it make a difference since the laughing and tears (crying) are being done by one subject (the narrator of the sentence)? I like to use commas with all my coordinating conjunctions that connect independent clauses. Please inform me if I should reconsider my punctuation because of other contextual or grammatical factors. Thanks.
    The problem in this sentence is not the comma use, but the conjunction choices.
    I would remove the initial "and" replacing it with "as" (with no comma) and then remove the initial "as" replacing it with "while"--this not only flows better, but it paints a clear picture of this man tearing up while he is laughing at the sight of these children fighting.

    "Peals of delighted laughter burst forth as tears formed at the corner of his eyes, while he watched the children fight."

    However, if I were using this sentence in my book, I would write it as follows:

    "Peals of laughter burst forth as the corners of his eyes welled up with joyful tears, while he amusingly watched the children fight."
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