ACT® · English: Sentence Structure and Formation
Run-Ons That Pass in Conversation
A run-on joins two complete sentences with no mark or too weak a mark. It can sound fine out loud because your voice supplies a pause, but writing needs a real joint: a period, semicolon, or comma plus conjunction.
Say 'I was tired I went to bed' out loud and it sounds like a normal thought trailing from one idea to the next. Your voice drops slightly between 'tired' and 'I,' and that tiny pause does the job a punctuation mark would do on paper. The test ignores that pause completely, because the pause isn't written down. On the page there are two complete sentences sitting next to each other with nothing holding them apart, and that's a fused sentence, one of the two ways a run-on happens.
Take 'Nobody answered the phone I left a message.' Three repairs work equally well: a period ('Nobody answered the phone. I left a message.'), a semicolon ('Nobody answered the phone; I left a message'), or a comma plus a coordinating conjunction ('Nobody answered the phone, so I left a message'). All three mark the boundary the voice only hinted at. Longer run-ons just stack the same problem. 'It rained we stayed home we baked bread' has two joints, not one, and each needs its own fix: 'It rained, so we stayed home and baked bread.' Fixing only the joint your ear catches first and leaving the second one fused is the trap.
This sits right next to the comma splice, which is the same error at a slightly stronger joint: 'I was tired, I went to bed' uses a comma alone where a comma can't do the whole job. Both the fused version and the spliced version join two complete sentences with a connector too weak to hold them, and the test treats them as the same underlying fault.
Key terms
- run-on
- Two or more complete sentences joined with no mark or too weak a mark between them.
- fused sentence
- A run-on with no punctuation at all between two complete sentences.
- comma splice
- A run-on that uses only a comma to join two complete sentences, which isn't strong enough on its own.
- independent clause
- A group of words with a subject and verb that can stand alone as a complete sentence.
- coordinating conjunction
- A joining word like so, and, or but that can pair with a comma to link two complete sentences.
Watch it explained
- How it worksHow does speech supply a pause where writing demands an actual mark, and why does the ACT ignore that pause?
- Worked exampleWalk me through repairing 'Nobody answered the phone I left a message' with the three strongest joints.
- Going furtherWhat happens when a run-on carries three clauses, as in 'It rained we stayed home we baked bread'?
- Ties togetherHow does a conversational run-on connect to the comma splice, given that both join clauses too weakly?
Check yourself
End of topic.