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Textbook
Introduction
1. ACT Math
2. ACT English
2.1 ACT English intro
2.2 Punctuation
2.3 Conventions of usage
2.4 Sentence structure
2.4.1 Comma splices
2.4.2 Fragments
2.5 Organization, unity, cohesion
2.6 Topic development
2.7 Knowledge of language
3. ACT Reading
4. ACT Science
5. ACT Writing
Wrapping up
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2.4.1 Comma splices
Achievable ACT
2. ACT English
2.4. Sentence structure

Comma splices

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On the ACT, this concept connects closely with the chapter on FANBOYS and joining clauses.

Here’s the key idea: a comma by itself isn’t strong enough to join two independent clauses (two complete sentences). If you see a comma separating what could be two complete sentences without a FANBOYS conjunction, you have a comma splice, and it’s incorrect.

The ACT is often sneaky with comma splices. They’re usually offered as tempting but wrong answer choices, and they’re easy to miss unless you’re actively checking for them.

Here’s a technique you can use to spot comma splices.

If a comma ever looks out of place, check these steps:

  • Read what comes before the comma. Is it a complete sentence?
  • Read what comes after the comma. Is it a complete sentence?
  • If the answer is yes to both of those questions, you can’t use a comma. Choose a period, a semicolon, or a comma + FANBOYS instead.

Example

Here’s how a comma splice question might appear in the ACT English section.

Experts are commenting on the declining quality of the education system, you know it’s not the same as it was.

A. NO CHANGE
B. system you
C. system and you
D. system; you

Choose the correct answer.

(spoiler)

Answer: D. system; you

Read the explanation below even if you chose the correct answer.

Option A. As written, you have a complete sentence followed by another complete sentence, with only a comma between them. That’s a comma splice, so this choice is incorrect.

Option B. This is worse because there’s no punctuation at all between two complete sentences.

Option C. This uses a FANBOYS conjunction, which can join independent clauses, but only when it’s paired with a comma. You need both the comma and the FANBOYS, so this choice is incorrect.

Option D. A semicolon can join independent clauses with no other help. It correctly fixes the comma splice, so this is the right answer.

Remember: don’t let the ACT pull you into a comma splice. Commas simply aren’t strong enough to join complete sentences.

Key points

If a comma by itself ever looks out of place, check these steps:

  • Read what comes before the comma. Is it a complete sentence?
  • Read what comes after the comma. Is it a complete sentence?
  • If the answer is yes to both of those questions, you can’t use a comma. Opt for a period, a semicolon, or a comma + FANBOYS instead.

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