How to properly connect clauses on the ACT & SAT

We've talked about how to identify independent and dependent clauses. However, the ACT and SAT are a little more nuanced than that. Rather than simply testing your ability to identify clauses, the exams test you on your ability to link clauses together. Knowing which punctuation marks to use is one of the most frequent concepts you'll encounter on the ACT and SAT.

The first thing you want to do is read the underlined portion and insert a slash between the two clauses. Then, re-read each clause again and determine whether it is independent or dependent. From there, use the following rules to determine what punctuation you need.

Independent Clause + Independent Clause

If you have two independent clauses, you can

  • Create two sentences, separated by a period
  • Split the two clauses with a semicolon ( ; )
  • Split the two clauses with a comma and a FANBOYS conjunction (For, And, Nor, But, Or, Yet, So)
  • Split the two clauses with a colon ( : )

Though there are multiple ways that you can connect two independent clauses, a comma by itself is not one of them. Think of a comma as a flimsy punctuation point that needs extra support from a FANBOYS word. In contrast, the period, semicolon, and colon are stronger anchors. Therefore, they don’t need the extra support from FANBOYS conjunctions.

Dependent Clause + Independent Clause

If you have a dependent clause and an independent clause, keep the following rules in mind.

  • When the dependent clause comes first, separate the clauses with a comma.
  • When the independent clause comes first, leave it alone and don’t put in any new punctuation.

When we link a dependent clause with an independent clause, the rules become much simpler. The ACT and SAT more often construct sentences with the dependent clause in the beginning, so you should feel comfortable inserting a comma where appropriate. However, be prepared for sentences where the dependent clause comes at the end.


She scored an A+ on the exam even though she didn’t study at all.

B. exam; even though
C. exam, and even though
D. exam even, though

It’s likely your instincts are telling you to separate the two clauses with something. However, if we look to answer choices B, C, and D, all introduce new grammar mistakes. Both B and C are wrong because they are using rules that only apply when connecting two independent clauses together. D is incorrect because the comma breaks the two clauses at an awkward spot. Therefore, the correct answer choice is A.

Dependent Clause + Dependent Clause

If you find a sentence with two dependent clauses, you’re going to have to tinker around a little more. Every sentence needs at least one independent clause, so you’re going to have to transform one of those clauses.


Though mothers agree on the benefits of a schedule for infants, when they don’t agree on the exact timing of those schedules.

B. infants; when they don’t agree
C. infants, when they don’t agree
D. infants, they don’t agree

Currently, this sentence is made up of two dependent clauses. The first clause opens with the minor conjunction “though” and the second with the relative pronoun “when.” Answer choices B and C only change the punctuation points, making no changes to the wording. Punctuation alone will not fix the problem, since you need at least one independent clause for a proper sentence. D changes the second clause into an independent clause, thus correcting the grammar error.

Notice what's underlined and what's not.

Finally, pay close attention to the parts of the passage that are underlined and those that are not. Remember that if something isn’t underlined, it must be left alone. There will be awkward sentences that you would like to rewrite in your own style. However, if it’s not underlined, you must leave it alone and tinker only with the underlined region.


Amanda spent months researching the origins of the universe, she finally finished her report for astronomy class.

B. Amanda spends months
C. After spending months
D. Amanda spent months;

Again, your instincts may tell you “I have two independent clauses so I need either two new sentences, a semicolon, a colon, or a comma and FANBOYS word.” However, notice that only the beginning of the first clause is underlined. The rest of the sentence must remain unchanged. That means we must change the first clause to make it fit in with the rest of the sentence. The only answer choice that correctly does this is C. By staying flexible with our edits and zeroing in on the part of the sentence we can change, we aren’t led astray by distracting answers.

For more tips, download our guide to the 6 skills you need to master for the SAT and the 6 skills you need to master for the ACT.

Need more individualized advice?

The recommendations above are general suggestions. If you have specific questions about your individual test prep plans, reach out to our experts here. We’re happy to help in any way we can.

Related Posts

How To Identify Independent and Dependent Clauses
How To Use Colons

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Jon Chang

About Jon Chang

Jon holds master’s degrees from Johns Hopkins University School of Medicine and NYU. He has helped students of all ages prepare for standardized tests, including the SAT, ACT, PSAT, GRE, and MCAT. Jon firmly believes that every student can achieve top marks on any test with the right amount of effort applied in the right direction. He goes beyond rote learning and teaches creative problem-solving as a method for better understanding of any material. Jon’s work has been featured on and in Scientific American and Popular Mechanics. 

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