I often get baffled as I think about where to use comma in the sentence and where not to do so. Examples:

1. As he left the Mayor's office , people surrounded and questioned him with serious curiosity.

2. After the meal had concluded (why is no comma used here?) the chief of police appeared on the scene .

I know that two clauses could be separated by the use of FULLSTOP, COMMA before FANBOYS, or by using the semicolon... But none of the them is used in the second sentence and also in the first sentence only comma is used and not any of the FANBOYS word after comma is used. Why?

  • 2
    Why is no comma used in the second example? Because you decided not to include it! There's no absolute grammatical rule governing your choices here - the comma is equally "optional" in both examples. But note that both sentences contain adverbial clauses that can't exist as standalone sentences, so you can forget about including any extra full stops. Aug 1, 2017 at 12:31
  • 1
    I think there should be a comma in the second sentence as well as the first
    – Sean
    May 7, 2018 at 17:49
  • Related.
    – tchrist
    Nov 24, 2022 at 21:25

3 Answers 3


The purpose of the comma is to clarify written text. You could put a comma after the introductory phrase in both examples, if it helps clarity. In speech, the phrases form intonation groups, and a comma can help mark the boundaries of such groups. You could also leave the comma out. Rules based grammar checkers tend to put in more commas than are required for understanding.

By "fanboys" I guess you mean a coordinating conjunction (For, And, Nor ...). We do often use commas before coordinating conjunctions, but this is a guideline rather than a rule.


In some cases, a comma helps prevent a possible misreading of the sentence subject as the object of the introductory phrase. A comma helpfully separates the subject -- chief of police in the example -- from a preceding verb (concluded) that has nothing to do with it. Without the comma, it can read as if the verb acts on the subject:

"After the meal had concluded the chief of police..."

That might momentarily sound like the meal "concluded" (killed?) the police chief.

This may seem funny or ridiculously picky. Still, even tiny bumps in comprehension are to be avoided. By the end of the sentence, you would not misunderstand it; reading the verb "arrived" makes it clear that the police chief is the subject. But before that, there can be a momentary pause or glitch in comprehension. The comma promotes the smoothest reading.


I suggest you use commas in every introductory phrase. 1. You avoid confusion. 2. You stop debating with yourself whether to use a comma or not.

Some authors leave the comma out for stylistic purposes ... but I think they are the minority. And their writing gets confusing at times.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .