Punctuation

Independent clauses

An independent clause has a subject and a verb. You can usually just tell: if it sounds like it could stand on its own, or like a complete thought, it's an independent clause and therefore a complete sentence by itself. A few examples:

• The committee reached a compromise after weeks of unproductive debate.
• The engineer revised the design so that it could withstand greater pressure.
• The student who had submitted her essay late asked for additional feedback.

Dependent clauses

Dependent clauses can't stand on their own. You don't need to memorize grammar terminology; just learn to recognize these four common patterns.

Common sentence-structure patterns

These are the shapes you'll see over and over on the ACT. Getting fast at spotting them makes every boundary question easier.

What they are. Run-ons are where you have two complete sentences connected by only a comma, only a FANBOYS, or by nothing.

On the ACT, they're usually tested as incorrect answers when you see that there are answers with periods, semicolons, comma+FANBOYS, or colons (which we'll talk about soon). However, we'll see some where they're testing on their own.

Let's revisit this problem. We already saw that there were two complete sentences. One up to the word "art" and another from "in 2016" to the period. A separates them with nothing, C with only a FANBOYS ("and"), and D with only a comma ("and").

Revisiting another problem. We already know that B is an incorrect use of a semicolon, but notice that C and D create Run Ons.

Here we see an example of a question where there are no ‘Complete Complete’ punctuation options nor a colon. You can identify that B, C, and D create Run Ons, while A creates a common sentence structure of Independent – Dependent as we saw at the beginning of this guide.

And another nearly identical problem.

Commas are mostly tested in two different ways: to bookend interjections and to separate independent and dependent clauses. Interjections have to be surrounded by two commas, or as we'll see, with dashes. However, it's much more common to see this done with commas.

The other test of commas follows this rule: on the ACT we ALWAYS separate independent and dependent clauses.

Checkout this question. If we plug in answer choice J, we see that we add a comma after “centuries”. The sentence then reads “For instance, Baniwa women have farmed distinctly flavorful chili peppers for centuries, using indigenous agricultural techniques, to create a seasoning called pimenta jiquitaia.” When we take out the bolded text now surrounded by commas, the sentence flows: Baniwa women have farmed distinctly flavorful chili peppers for centuries to create a seasoning called pimenta jiquitaia.

Another quick example. B) Since we can remove the phrase "a medieval author and dramatist" choice B is correct. Notice that A) has a dash after “dramatist”. As we’ll see, that would have worked if there were also a dash after “author”.

Here's two more examples that work the exact same way.

Let's check out an example of the second way the ACT tests comma usage: separating Independent and Dependent clauses. Notice that with A) and B) we do not have a required complete up to the colon or up to the semicolon. We can see the common dependent-independent structure of the sentence, which need to be separated. Thus C) is correct.

If we read the sentence, we can see that structure again goes Dependent-Independent. “Even more fortunately” is dependent and “he had already created…” is independent. Thus, we need a comma between the two, and D) is correct.

There are their own type of question. Though it looks like it's testing comma usage, you should handle it differently. The name of the question-type tells you exactly what it is: when you see a title/occupation right before a name. "ACT tutor Majid Hasan", "theoretical physicist Robert J. Oppenheimer", "cartoon character Krusty the Clown", etc.

The vast majority of the time, no commas before or after the name.

Check out two examples.

The exception: every once in a while, you'll need a comma after the name (never before) if there's an interjection right after the name (or maybe a dependant clause). "The book was written by legendary journalist Bob Woodward, who won a Pulitzer prize the following year." Here we'd need a comma after the name to separate the independent and dependent clauses.

Here's an example of an interjection after the name. See the interjection that starts right after "Ien Chi"? So no comma before the name, but we need one right after.