Why is the comma needed in "I entered the hallway, and knocked on the door." I have seen this use often in books and think it is incorrect.
You're right, no comma is needed. This is a sentence with a compound predicate and a single subject. If there were a second subject, then it be would a compound sentence, and a comma would be required.
I entered the hallway and knocked on the door.
I entered the hallway, and I knocked on the door.
|link comment||answered Jan 26 at 19:28 Lewis Neidhardt Grammarly Fellow|
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