ACT English Sentence Fragments and Run-Ons: Fix Every Structural Error Instantly

A complete sentence needs a subject, a verb, and expresses a complete thought. Test: Can this stand alone as a sentence? If not, it's a fragment. Fragments are incomplete thoughts. Example: "Running down the street." (incomplete; who is running? what happened?). Run-ons are two complete sentences joined incorrectly. Example: "She studied hard she passed the test." (two complete sentences with no connector). To fix fragments, add what's missing (subject or verb). To fix run-ons, separate them with a period, semicolon, or add a conjunction.

Fragment: "Because the test was hard." Fix: "Because the test was hard, she studied all night." Run-on: "I like pizza and I like pasta." Fix: "I like pizza and pasta" (combine) or "I like pizza. I like pasta." (separate).

Mistake 1: Thinking a long clause is complete just because it has many words. "Although the team practiced every day and worked on fundamentals and improved significantly" is still a fragment because "although" makes it dependent. Fix: "Although the team practiced every day and worked on fundamentals and improved significantly, they lost the game." Mistake 2: Using a comma to join independent clauses (comma splice). This is a run-on error. Mistake 3: Adding a dependent clause to an independent clause with a comma is correct, but using just a dependent clause alone is a fragment. Always verify: Is there a subject? Is there a verb? Does the thought complete by itself?

During practice, mark every sentence and ask the three questions. This habit catches fragments and run-ons before you finish reading.

Sentence 1: "Running fast to catch the bus." Fragment (missing what happened). Fix: "I was running fast to catch the bus." Sentence 2: "She studied hard she passed the test." Run-on (two independent clauses). Fix: "She studied hard, so she passed the test." or "She studied hard; she passed the test." Sentence 3: "Because the weather was bad." Fragment (dependent clause alone). Fix: "Because the weather was bad, the game was cancelled." Sentence 4: "The team won the championship and they celebrated all night." Run-on? Actually correct if you see "and" as coordinating the two independent clauses. With proper comma, it's fine: "The team won the championship, and they celebrated all night." Sentence 5: "To improve your score." Fragment (infinitive phrase). Fix: "To improve your score, practice daily." Identify each error type and apply the fix.

Find 10 fragment/run-on questions from a practice test. For each, identify the error and apply the fix. By the tenth question, fragment and run-on errors will be obvious.

Fragment and run-on questions appear on nearly every ACT English test. Because the test is simple (does it stand alone? are two independent clauses joined correctly?), this is a high-return skill. Mastering fragment and run-on identification picks up 2-3 points on the English section because these errors are so common and the fixes are mechanical.

Drill the completion test (subject, verb, complete thought) daily this week. Mark every sentence you encounter and verify it passes all three tests. By test day, you'll spot fragments and run-ons faster than any other grammar error.