Letters make up words, words make up fragments, fragments make up sentences, and sentences come together to form a piece of writing. Whether it’s a novel, a scientific article, or even a poem, they’re all made up of sentences.  When it comes to the SAT, dissecting sentences and identifying the parts of them successfully is imperative to getting a good score and being a good writer yourself!

Let’s start off by going over the parts of a sentence and ways they can go wrong, and then we’ll get into the types of sentences you may see on the SAT and how you can improve them.

Kickstart Your SAT Prep with Test Geek’s Free SAT Study Guide

In each sentence, there must be a subject and a verb.  Simply, the subject must either be doing something, or we must have something to say about it.  The subject and verb also have to agree for it to be a correct sentence, but we can get into that in another blog post.


Let’s say you’re missing either the subject or the verb. This is called a fragment. A fragment can not be a complete sentence because there is no action or description of the subject, or maybe there’s no subject at all. You wouldn’t say “Ate the last piece of cake,” because who? WHO ate the last piece of cake?!? Inversely, you wouldn’t just say “Maybe Tobin.” because WHAT about Tobin?  Did he maybe eat the cake?  We’ll never know unless you put the subject and its verb together into a complete thought.

This is oversimplified for clarity’s sake. Frequently on the SAT, you’ll see questions asking you to improve the sentence, and the sentence in question just a long fragment full of detail and fancy vocab to throw you off and trick you into thinking it’s a complete sentence.  For example, a fragment could look like this:

“Tobin, the hungriest child in the world who is crouching in the corner so he can hide what he did.”

On paper you might think, okay Tobin = subject, crouching = verb, but that tricky “who” in the middle of the sentence makes the fact that he is crouching a detail about him rather than the main action of the sentence. College Board loves to throw what we call non-essential phrases into fragments to make them look like a full sentence, but if you read the sentence out loud something sounds off.

Quick tip: Trust that instinct to read the sentence aloud, but probably only while you’re studying at home or with your tutor, and not in the testing room. For everyone’s sake. <-There’s another fragment example for you. Fragments can sometimes be used as full sentences in writing, but not on the SAT. Save the stylized casual voice for your diary.

In short, a sentence needs to have a WHO and a WHAT or it is a fragment, and therefore illegal on the SAT.

She’s alone so she can read aloud as much as her heart desires.

What if there’s more than one subject verb set in the sentence?

In a case with correct punctuation, you have a compound sentence! If there is no punctuation, then there’s a really good chance you have a run-on sentence, which is also illegal. Here’s an example of a run-on sentence:

Tobin is acting suspicious because he knows the cake was spoken for but he ate it anyway because he’s always hungry and doesn’t care about dibs apparently I wish he didn’t come to the party.

A complete thought is anything that could be a sentence by itself. When you have more than one complete thought in a correct sentence, they are separated three different ways: comma + conjunction, semicolon, or period. The complete thoughts are underlined in this example:

Tobin is acting suspicious because he knows the cake was spoken for but he ate it anyway because he’s always hungry and doesn’t care about dibs apparently I wish he didn’t come to the party.

To avoid the grammar police coming for you, use punctuation!  You can improve an SAT sentence by splitting up the subject-verb sets into separate complete thoughts and making them work together. Sentences with more than one subject-verb set need separation for clarity. Punctuation was born for this.

Tobin was hungry, so he ate the last piece of cake.

Tobin was hungry; he ate the last piece of cake.

Tobin was hungry.   He ate the last piece of cake.

Using these choices, this is just one way you could improve our run-on sentence:

Tobin is acting suspicious because he knows the cake was spoken for, but he ate it anyway. He’s always hungry and doesn’t care about dibs, apparently. I wish he didn’t come to the party.

The good news is that the SAT will only have one correct answer, so even if you see all three of these methods in your answer choices, only one will improve the sentence correctly. It’s all about the details, so make sure you’re looking for the who and the what amidst the descriptive fluff to determine if punctuation is going to help, or if you need to restructure the sentence entirely.

Quick tip: If you’re a visual learner, it can be helpful to underline the subject-verb sets in the sentence to break it up and see what you’re working with.

Visually deconstructing the sentence by underlining its parts can help you improve it.

Types of Sentences

Now that we’ve talked about the parts of a sentence, let’s touch on the types of sentences you’ll see on the SAT.  Knowing what you’re looking at can help you dissect them effectively to improve their grammar.

Simple – A simple sentence has only one subject-verb set. It’s a complete thought on its own.

                Tobin ate the last piece of cake.

                Subject = Tobin

                Verb = ate

Compound – A compound sentence has more than one subject-verb set separated by a comma, conjunction, or semicolon. It can be broken up into 2 separate, complete sentences with a period.

                Tobin ate the last piece of cake, so he is dead to me.

                Tobin ate the last piece of cake. He is dead to me.

                Subjects = Tobin, he

                Verbs = ate, is

Complex – A complex sentence is a complete thought, with a fragment thrown in for fun.  It can be broken down into a complete sentence (an independent clause), and at least one fragment (a dependent clause) piggybacked on to add detail or extra context.

                Like a real jerk, Tobin ate the last piece of cake.

                “Like a real jerk” is a fragment acting as the dependent clause, because it depends on the independent clause, “Tobin ate the last piece of cake.” to make sense.

Declarative – Declarative sentences are making a statement.  They are declaring something, stating a fact, sharing information, explaining something, or conveying information of some sort.  

Tobin ate the last piece of cake

It has been declared that Tobin is a dirty cake thief.  Let the world know.

Interrogative – Interrogative sentences are asking a question.  It can be a yes or no question or more complex, but they all have the same goal: to acquire information.

Why would Tobin eat the last piece of cake when I called dibs?

Exclamatory – It’s only appropriate to end our Tobin example with an exclamatory sentence. Exclamatory sentences convey strong emotion. They typically end with an exclamation point.

                I am never speaking to Tobin again because he is a cake-stealing goblin!

Let the world know how much you hate Tobin with an exclamation point for extra *spice*.

“Tobin must be stopped!” Is a great example of an exclamatory sentence, and also true. He’s a monster.

How will this all translate on the SAT?

You use all of these types of sentences every single day when talking to your friends, doing your homework, and live-tweeting The Bachelor.  It’s nothing new for you to formulate multiple thoughts into one sentence that helps you communicate clearly, and it shouldn’t be any harder than that on the SAT. Now that you know the different parts of the sentence, and the ways they can go wrong, you can deconstruct the SAT questions to improve them and succeed in the Writing section.

Try asking yourself these questions when trying to figure out if a sentence is correct or not:

  • Who?: What is the subject or subjects?
  • What?: What is the subject doing or how is it described?
  • Do the subject and the verb come together to create a complete thought, with or without the fragmented details College Board loves to trick you with?
    • If the sentence does not come together as a complete thought, it is incomplete or incorrect.  A sentence must have at least one subject and corresponding verb to be complete.
  • Is there more than one complete thought within the sentence?
    • If there are 2 or more complete thoughts in a sentence, it may be a compound sentence.  Compound sentences require punctuation whether its a period, semicolon, or comma.  If there’s a complete thought, but it only has a fragment or two accompanying it, it could be a complex sentence.  
  • Can the punctuation in this sentence be improved?
    • Adding punctuation and/or conjunctions to a sentence without any may help rescue the sentence from run-on status.  If there are multiple subjects and verbs and no punctuation, chances are it’s a run-on, and incorrect.  Compound sentences will have two complete thoughts separated by some sort of punctuation. Complex sentences will have one complete thought and at least one dependent clause (or fragment) to provide detail and context, also sometimes marked with punctuation or conjunctions.

Run-on sentences and sentence fragments can get tricky on the SAT. Your best bet is to deconstruct the sentence to help determine the subjects and verbs and what type of sentence you have.  From there you can decide how to either make it a complete thought, or how to connect multiple complete thoughts into one cohesive, improved sentence.  

Kirsten Mann
Kirsten is the Operations Coordinator at Test Geek. She has a 35 on the ACT Reading Test and enjoys sarcasm and pop culture references.

SAT Writing: Subject and Verb Agreement Explained

Previous article

Descriptors on the SAT: Adjectives, Adverbs, Comparisons and Superlatives

Next article

You may also like


Comments are closed.

More in ACT English