A comma-splice sentence can be fixed by replacing the comma with a semicolon, a colon, a conjunction or a full stop. But often the problem runs deeper: habitual comma-splicers can’t tell the difference between a clause and a phrase. A clause needs a subject and a main verb, and can form a sentence as long as it is not subordinate to another clause. A phrase cannot form a sentence on its own but can, if linked to a main clause, extend one. Often all that is needed to divide a phrase from a clause, or another phrase, is a comma.
