Lessons · Teaching · fragments, run-ons and the comma splice
One sentence, and the three ways it stops being one
A sentence needs a subject and a finite verb and must be able to stand alone. A fragment is missing one of those. A run-on joins two complete sentences with nothing between them. A comma splice joins two complete sentences with only a comma, which is the error the test asks about most.
Hone is a place to practise a career, one idea a day. This is one of its lessons, written out in full and free to read without an account.
In beta. This lesson was written for Hone and has not yet been checked by a state certification officer. Practice material, not professional advice. What that means.
What it is for
You are about to mark this in other people's writing for a living, which means you need to name it, not only feel it. And the fix teaches the idea: a comma splice is repaired by a full stop, a semicolon, or a comma plus a joining word, and choosing between those three is a decision about how closely the two ideas are related.
How to think about it
Find the finite verbs. Two of them with no joining word between is a splice or a run-on. Then read each half on its own: if both stand up as sentences, you have two sentences and must choose how to join them. If one does not stand up, you have a fragment and must attach it to the sentence it belongs to.
Worked example
'The bell rang, the children left.' Two sentences, one comma. That is a comma spliceBoth halves stand alone, so a comma alone cannot hold them.
Fix it with a full stop, a semicolon, or 'and': all three are correct and mean different thingsThe semicolon says the two are closely tied; the full stop says they are separate.
'Because the bell rang.' A subject and a verb, and still a fragmentBecause makes it dependent. It has to lean on a main clause.
'Running down the corridor, shouting.' No finite verb at all, so no sentenceTwo participles are not a verb that a subject can do.
Your turn
Name the error of joining two complete sentences with only a comma.
Two complete sentences joined by a comma alone is a comma
Solve one, graded on the server
The trap
Believing length decides. A very long sentence can be perfectly grammatical and a three-word fragment can be wrong. The test writers use long correct sentences as distractors precisely because length feels like an error.