Sentence Structure: What Is Sentence Structure? Definition and Examples

By Carly Forsaith, updated on June 19, 2023

If you want to learn more about sentence structure, this article was written for you. You're about to learn what sentence structure is, how to make a sentence, and the elements you can use to beef up your sentences.

  • A sentence is a set of words that comes together to convey a meaning.
  • It consists of a subject and a predicate.

This guide is part of our free online Grammar Book.

What is a Sentence?

I suppose the first question we need to address is, what exactly is a sentence? It can be many things, really. It can be short or long, simple or complex. It can ask a question, give a command, make a statement, and do several other things. But what is a sentence at its core, and what do they all have in common?

A subject is a thing or person that does the action of the verb or has the action of the verb performed on it. A predicate is made up of a verb, at the very least, and at most, all the other elements that describe the action. See the following examples where the subject is in bold and the predicate is underlined.

She goes to the gym every day.

The petition was signed by thousands

Bees carry pollen from one flower to another

The most basic form of a sentence only contains a subject and a verb. To make it a little more complex, you can add more clauses. We'll get onto that later.

Okay, okay, there's one exception (there always is!): an exclamatory sentence can be just a verb and nothing else. For example: 'Run!'

There are two things you should never forget about sentences:

Different Parts of Sentence Structure

As we've already covered, sentences are made up of a subject and a predicate. Predicates include, at the very least, one verb. But they can also contain a whole lot more than that. There are tons of fun parts of a sentence you can use in your predicate, which we're going to go over in this section.

But first, you need to understand what a clause is.


Clauses are essential to understand because they're what sentences are made of.

There are two kinds:

A clause is a group of words that contains a subject and a predicate. Sound familiar? Yup, that's what sentences are made of, too. That's why you only really need one independent clause to form a sentence because, being made up of a subject and a predicate, they form a complete thought.

Here's an example of an independent clause:

Ben asked us to wait.

But you also can get dependent clauses, and they can't stand on their own because they don't form a complete thought, so they get tacked on to an independent clause to form a longer, more complex sentence.

Here's an example of a dependent clause:

until he arrives.

Now let's put these two clauses together to form a complete sentence:

Ben asked us to wait until he arrives.

You can learn more about clauses here.

Direct Object

Direct objects are a great addition to any sentence. They give more information about the verb's action—specifically, who or what the action is done to.

In the following sentence, 'flowers' is the direct object because it's the thing receiving the verb's action (being picked).

I'm picking flowers for my mom.

Look at the following sentences for more examples of direct objects (underlined):

We watched a movie then fell asleep.

Why are they talking to the tree?

Dogs love to eat bones.

Top Tip! Direct objects are always nouns.

Check out this article to learn more about direct objects.

Indirect objects

While direct objects receive the verb's action, indirect objects receive the direct object. In the following sentence, Louisa is the indirect object because she is receiving 'lunch,' which is the direct object of the verb 'bought.'

I bought Louisa lunch.

Here are some more examples of indirect objects (underlined):

The clerk lentme a pen.

You must pay the landlord a security deposit.

They awarded everyone a medal for participating.

To learn more about indirect objects, check out this article dedicated to them.


You can have subject complements and object complements, and both give additional information about—you guessed it—the subject or object.

  • Complements are essential to the meaning of the sentence they are in, so they can't be removed, and they are usually nouns, pronouns, or adjectives.

Here are some examples of complements in a sentence (underlined):

My bike is new.

This song makes me happy.

Who made you the boss?

Here's an article about complements. 


Another type of word you can use to enrichen your sentences is modifiers. They let you tell the reader about how, when, where, or how something is. Modifiers can be adjectives, adverbs, prepositional phrases, or determiners.

Take a look at the determiners (underlined) in the following sentences:

I'm going on a date with the man I told you about last time.

My favorite book of his is Extremely Loud and Incredibly Close. 

The blue house at the end of the street is mine.

This article will teach you all you need to know about modifiers.

Types of Sentence Functions

Now we've covered some of the basics of what makes up a sentence and the different words you can use in one. It's time to learn about the various types of sentence functions.

There are four:

  • Interrogative
  • Exclamatory
  • Imperative
  • Declarative

Interrogative Sentences

Want to ask a question? Interrogative sentences are your friend. They allow you to elicit information from someone and always end with a question mark.

Here are some examples:

What time do you wake up in the morning?

Have you seen the latest James Bond?

Where do you stand on the debate we had in class today?

Exclamatory Sentences

You can use exclamatory sentences to express strong emotions like surprise, anger, disgust, pain, and so on. As the name indicates, they end with an exclamation mark.

Wow, you look amazing!

That was the worst meal ever!

I think I broke my leg!

Imperative Sentences

You can use an imperative sentence if you wish to give a command, make a request of someone, or give instructions. You might remember me mentioning at the start of this article that the shortest possible sentence is imperative because it doesn't require a subject (it's always 'you'). Imperative sentences can be longer than just one word, though.

Rex, sit!

Note to self: go to the store on the way home. 

Call me ASAP.

Declarative Sentences

I left these types of sentences until last because the easiest way to explain them is that if a sentence isn't any of the other types we've just covered, it's a declarative sentence. It's a way to make a statement and show you're confident that your information is accurate.

Here are some examples of declarative sentences:

Oh hey honey, I'm just heading to the store.

Grammar is fun.

Let's go and say hi to dad.

Types of Sentence Structure

Now that we've learned about the different types of sentence functions let's look at the other sentence structures. As discussed earlier, a sentence can be pretty basic and only include one clause. Or, it can consist of multiple clauses, a mixture of dependent and independent ones, and additional elements like prepositions. The more you add, the more complex your sentence becomes, and that's when you're looking at different types of sentence structure.

There are four in total:

  • Simple
  • Compound
  • Complex
  • Complex-Compound

Simple Sentence Structure

A simple sentence is just one independent clause comprising a subject and a predicate. Like all sentences, it can also contain direct and indirect objects. Remember, the subject is the noun doing the verb, and the predicate describes what the verb's doing.

Let's take a look at some examples of simple sentences:

We took a long walk through the forest.

Everyone has cast their vote. 

Are you staying in a hotel?

An independent clause must express a complete thought, and so must a simple sentence.

Compound Sentence Structure

Two independent clauses joined together into one sentence make up a compound sentence. You can connect them with a semicolon (;) or a coordinating conjunction (for, and, nor, but, or, yet, so).

I'm worried about Tom; he hasn't been himself lately.

You can go cold turkey or try nicotine gums.

She ran for the bus so she wasn't late for school.

Interestingly, it becomes dependent once you add a conjunction to an independent clause. "So she wasn't late for school" can no longer stand alone as a sentence, whereas "She wasn't late for school" can. But still, the important thing is that your two clauses are independent, to begin with, for your sentence to be a compound one.

Complex Sentence Structure

Complex sentences are made up of a dependent and an independent clause. Some words that commonly connect the dependent clause to the independent one are 'who,' 'which,' 'since,' while,' 'because,' and 'if.'

She approached the boy who was sitting all alone in the sandpit.

While the proposal was solid, they knew they could do better.

I've been waiting here since 12pm! 

Compound-Complex Sentence Structure

True to their name, compound-complex sentences are a crossover between a compound and a complex sentence, as you might have guessed. It contains at least two independent clauses and at least one dependent clause.

There was some drama because of the break-up; everyone could feel the tension in the air.

We are struggling to deicde where to go on vacation this year as there are so many amazing destinations, which makes it very difficult to choose.

She graduated with flying colors but she still isn't satisfied because it's just in her nature.

Common Sentence Structure Errors

Let's review the most common mistakes made regarding sentences, so you can avoid them and adorn your writing with perfect sentences!

Sentence Fragments

Sentence fragments are incomplete sentences because they're missing some essential bits. That could be a verb or a subject or trying to make a dependent clause pass as a complete sentence.

Here is an example of a sentence fragment:

Because I said so. 

This is a commonly heard sentence fragment from parents' mouths. The conjunction 'because' is a giveaway here, showing that this is a dependent clause. A dependent clause can't stand alone without an independent clause to depend on. This is a sentence fragment.

A complete sentence might look something more like this:

You can't go to the party because I said so. 

Here are some more examples:

The same as last week: nothing at all. (no verb)

Getting into all sorts of trouble, probably. (no subject)

The one standing in the middle. (dependent clause)

Some writers use sentence fragments as a stylistic choice to make an impact or draw attention to specific information. It's okay to do this if you're one hundred percent sure your readers will know what you're doing and won't just think you've made a writing mistake. And never use it in academic writing.

Also, sentence fragments are a lot more acceptable in conversation. For example, when you answer a question, you'll often use a sentence fragment to respond.

Run-On Sentences

Run-on sentences are lengthy and complex for the reader to read. They lead to a lot of confusion and come across as amateurish. Eradicating them from your writing is one of the best things you can do for your credibility!

Run-on sentences happen when you combine two sentences incorrectly—there isn't enough punctuation or conjunctions or too many.

Here are some examples of run-on sentences and ideas on how you can fix them:

The weather's too cold to go out, I will stay in, read a book.
The weather's too cold to go out so I will stay in and read a book.

I enjoyed his company but there was no chemistry and the conversation didn't flow although he was a gentleman. 
I enjoyed his company but there was no chemistry and the conversation didn't flow. Although, he was a gentleman.

My cat's been missing for weeks I'm very worried.
My cat's been missing for weeks; I'm very worried.

Remember that a sentence should only convey one thought, maybe two if the clauses are separated by the proper punctuation. Suppose your sentence is trying to accomplish too much. In that case, it's likely a run-on sentence, and you can usually fix it by dividing the clauses into two sentences, inserting a semicolon, or using a comma and conjunction.

Incorrect Subject-Verb Agreement

Matching the verb's form to the subject is called subject-verb agreement. When the subject of the sentence is singular, that means there's only one thing or person performing the verb's action. Therefore, the verb form must be singular to match. Equally, if the subject is plural (two or more), so should the verb be.

Sounds simple, right? Yet incorrect subject-verb agreement is a widespread error.

Here are some examples of sentences that contain wrong subject-verb agreement:

She were afraid of the storm last night. ❌ (should be 'was')

Has you been to the new restaurant in town? ❌ (should be 'have')

The trains runs every hour on the hour. ❌ (should be 'run')

Non-Parallel Sentence Structure

Parallelism helps your sentences follow a similar structure by ensuring the repetition of certain grammatical elements. Sentences that lack parallel structure can come across as a little messy and confusing.

Look at the following sentence, for example:

I like to jog, paint, and eating pastries.

Notice how the verb 'eating' is in the present participle tense while the others are in the present simple.

You can improve this sentence just by matching all the verbs to the same tense:

I like to jog, paint, and eat pastries.

The verb form is not the only factor in parallel structure, however. There are many factors in maintaining parallel structure, which you can learn more about in this article. For now, here are some examples of non-parallel structure corrected.

The waiter was friendly, helpful and paid a lot of attention to us. 
The waiter was friendly, helpful and attentive

Your teacher told us that you don't listen, that you don't put in any effort and you're disruptive in class. 
Your teacher told us that you don't listen, that you don't put in any effort and that you're disruptive in class.

My decision was influenced by my mother and because of my desire to achieve great things.
My decision was influenced by my mother and by my desire to achieve great things.

Concluding Thoughts on Sentence Structure

That concludes this article on sentence structure. I hope you found it helpful.

Let's summarize what we've learned:

  • All sentences need a subject and a predicate (except imperative sentences, which can be made up of only a verb).
  • There are four sentence function types: interrogative, exclamatory, imperative, and declarative. 
  • The sentence structure changes as you add more parts to it.
  • There are four sentence structure types: simple, complex, compound, and complex-compound.
  • Watch out for common sentence errors.

If you enjoyed this article, you might like our Grammar Book, an online database of articles just like this one that breaks down complex grammar concepts into easy-to-understand ideas.

We encourage you to share this article on Twitter and Facebook. Just click those two links - you'll see why.

It's important to share the news to spread the truth. Most people won't.

Written By:
Carly Forsaith
Carly Forsaith is one of the lead freelance writers for Carly is a copywriter who has been writing about the English language for over 3 years. Before that, she was a teacher in Thailand, helping people learn English as a second language. She is a total grammar nerd and spends her time spotting language errors on signs and on the internet.

Add new comment

Your email address will not be published. Required fields are marked * Newsletter
Receive information on
new articles posted, important topics, and tips.
Join Now
We won't send you spam. Unsubscribe at any time.