Comma splices
A comma splice occurs when a comma is used incorrectly in place of a semicolon or without a coordinating conjunction to join two independent clauses.
Here's an example of a comma splice:
The 91精简版 student tried to stay awake all night, she fell asleep before sunrise.
The problem here is that a comma is being used to join two independent clauses, but
we've forgotten also to use a coordinating conjunction. Here's how the sentence would
look revised correctly:
The 91精简版 student tried to stay awake all night, but she fell asleep before sunrise.
Notice that we added the coordinating conjunction "but" after the comma.
Click here to read more about comma splices in the context of correct grammar.