How to Break Down a Sentence Into Parts of Speech


Basic Sentence Structure

First, let’s define sentence structure

Unless you’re an English major, chances are you haven’t studied the mechanics of the language in quite some time. Sure, you can probably write and speak in complete sentences but that’s just the first step. Knowing what sounds right vs. knowing why it is right are two very different levels of mastery.

So, consider this a brief re-education on how sentences work. Before we get into the various types there are, let’s define what we mean when we talk about English sentence structure.


Tokenizing Words

We are going to break down a sentence into tokens using this simple example using the word_tokenize function.

This will result in the following output.

What the routine performed was tokenizing the words in the input sentence value for txt. Notice that it also tokenized the characters ‘,’ and the question mark ‘?’. Basically, it tokenizes the contents of the text in the sentence. If the character ‘?’ were a period ‘.’, it would be tokenized as well.

If you are missing a library or file, you might encounter the following error message:

Just simply run the last two commands from the console in your Python development environment.

Structure Examples

4 types of sentence structure

Now that we’ve tackled “what is sentence structure,” let’s look more in depth at its different types.

Simple Sentences

The most basic type of English sentence is the simple structure. This is when a sentence is composed of just one independent clause – a clause which contains a subject (the noun performing the action of the sentence) and predicate (the action being taken) and expresses a complete thought. Like all sentences, it can also contain a direct object (the noun receiving the action of a sentence) or indirect object (the object for whom the action is being done). 

A few simple sentence examples:

  • I didn’t go to the game.
  • She was correct.
  • The writer was out of ideas.
  • The movie was over two hours long.
Compound Sentences

The compound sentence combines two or more independent clauses with a coordinating conjunction (or, and, but, yet, for, nor, so) or a semicolon.

Here are some examples:

  • She was sick, so she didn’t go to school.
  • Greg kept his distance; he knew he was a dangerous man.
  • I was exhausted, but I worked all night.
  • Mom was still at work, and Dad was out to dinner.

Notice how all of these sentences could be broken into two: “She was sick. She didn’t go to school.” “Mom was still at work. Dad was out to dinner.” That’s because these sentences contain 2 independent clauses, which can be turned into simple sentences.

Complex Sentences

Complex sentences consist of an independent clause and a dependent clause. A dependent clause is an incomplete thought (e.g., “Although I was sick, …” “Because he was gone, …”) and thus needs to be attached to an independent clause. It’s also known as a subordinate clause.

Some complex structure examples:

  • If he was so funny, the whole crowd would have been laughing.
  • I went to dinner because I was hungry.
  • She turned her down because she was in love with someone else.
Compound-Complex Sentences

True to their name, compound-complex sentences combine the ideas behind both compound and complex sentences: they contain at least two independent clauses and a dependent clause. 

Because they can be pretty hard to parse, I’ve color coded the independent clauses, the coordinating conjunction/semicolon, and the dependent clauses. Let’s take a look:

  • Because he was injured, the team played with a short bench and their rivals beat them soundly.
  • I wondered what became of him; if he liked Chicago so much, it made no sense for him to up and leave.
  • The teacher gave Jimmy a time-out because of his bad behavior and we all laughed at himreveling in the chaos he had wrought.

Sentences contain a lot of moving parts, and these structures tackle just a small portion of sentence grammar. For a more comprehensive look at all the parts of a sentence, check out this video:

Tokenizing Regular Expressions

In this example, we are going to search for a word pattern in the sentence.

This results in the output:

When using ‘\w’ it is indicating to match whole words. No punctuation marks were returned, since we are only looking for words in the string of text. If we were to be specific, we can specify the word or pattern we are looking for.

There are different variations on how to match patterns. More resources on the types of option flags that can be used can be referenced from the following link.

Complex Sentence Structure

A complex sentence consists of an independent clause plus a dependent clause. (A dependent clause starts with a subordinating conjunction or a relative pronoun, and contains a subject and verb, but does not express a complete thought.)

 We missed our plane because we were late. Our dog We missed our plane because we were late. Our dog

  • We missed our plane because we were late.
  • Our dog barks when she hears a noise.
  • He left in a hurry after he got a phone call.
  • Do you know the man who is talking to Mary?

Here are some common subordinating conjunctions:

  • after, although, as, because, before, how, if, once, since, than, that, though, till, until, when, where, whether, while

Here are the five basic relative pronouns:

  • that, which, who, whom, whose

Meaning and Sentence Structure

"People are probably not as aware of sentence structure as they are of sounds and words, because sentence structure is abstract in a way that sounds and words are not . . . At the same time, sentence structure is a central aspect of every sentence . . . We can appreciate the importance of sentence structure by looking at examples within a single language. For instance, in English, the same set of words can convey different meanings if they are arranged in different ways. Consider the following:

  • The senators objected to the plans proposed by the generals.
  • The senators proposed the plans objected to by the generals.

The meaning of [first] the sentence is quite different from that of [the second], even though the only difference is the position of the words objected to and proposed. Although both sentences contain exactly the same words, the words are structurally related to each other differently; it is those differences in structure that account for the difference in meaning."—Eva M. Fernández and Helen Smith Cairns

Producing and Interpreting Sentence Structures in Speech

“The grammatical structure of a sentence is a route followed with a purpose, a phonetic goal for a speaker, and a semantic goal for a hearer. Humans have a unique capacity to go very rapidly through the complex hierarchically organized processes involved in speech production and perception. When syntacticians draw structure on sentences they are adopting a convenient and appropriate shorthand for these processes. A linguist’s account of the structure of a sentence is an abstract summary of a series of overlapping snapshots of what is common to the processes of producing and interpreting the sentence.”—James R. Hurford


A sentence fragment is a collection of words that looks similar to a sentence, but actually isn’t a complete sentence. Sentence fragments usually lack a subject or verb, or don’t express a complete thought. Whilst a fragmented sentence can be punctuated to appear similar to a complete sentence it is no substitute for a sentence.

Simple Sentences

Simple sentences are, unsurprisingly, the easiest type of sentence for students to grasp and construct for themselves. Often these types of sentences will be the first sentences that children write by themselves and they follow the well-known SubjectVerbObject or SVO pattern.

The subject of the sentence will be the noun that begins the sentence. This may be a person, place, or thing, but, most importantly, it is the doer of the action in the sentence.

The action itself will be encapsulated by the verb, which is the action word that describes what the doer does.

The object of the sentence follows the verb and describes that which receives the action.

This is again best illustrated by an example. Take a look at the simple sentence below:

Tom ate many cookies.

In this easy example, the doer of the action is Tom, the action is ate, and the receiver of the action is the many cookies.


Subject = Tom

Verb = ate

Object = many cookies

After a little practice, students will become adept at recognizing SVO sentences and forming their own. It’s important to point out too that simple sentences don’t have to necessarily be short.

For example:

This research reveals that an active lifestyle can have a great impact for the good on the life expectancy of the average person.

Despite this sentence looking more sophisticated (and longer!), this is still a simple sentence as it follows the SVO structure:

Subject = research

Verb = reveals

Object = that an active lifestyle can have a great impact for the good on the life expectancy of the average person.

Though basic in construction, it is important to point out that the simple sentence is often the perfect structure to deal with complex ideas. Simple sentences can be an effective way to provide clarity and efficiency of expression breaking down complex ideas into manageable chunks.

Simple Sentence Reinforcement Activity

To ensure your students have a strong grasp of the simple sentence structure, have them go through a photocopied text pitched at a language level suited to their age and ability.

On the first run-through, have students identify and highlight simple sentences in the text. Then, students should use various colors of pens to pick out and underline the subject, the verb, and the object in each sentence.

This activity helps ensure a clear understanding of how this structure works, as well as helping to internalize it. This will reap rich rewards for students when they come to the next stage and it’s time for them to write their own sentences using this basic pattern.

After students have mastered combining subjects, verbs, and objects into both long and short sentences, they will be ready to move onto the other 3 types of sentence, the next of which is the compound sentence.


Reinforcement Activity

Varying sentence structure in your writing

It’s incredibly easy to fall into the trap of having too many similarly structured sentences.

Thankfully, a few tweaks during editing can easily fix things!

Keep in mind, though, that you don’t need to change every sentence. Your go-to sentence structure might work fine some of the time.

If you’re struggling to come up with different types of sentences, or if you’ve got a sentence that isn’t working but you’re not sure why, you might want to check out June Casagrande’s book It was the Best of Sentences, it was the Worst of Sentences: A Writer’s Guide to Crafting Killer Sentences for lots of example and insights.

Next time you edit a piece of your writing — or someone else’s — pay close attention to sentence structure. Could a few minor tweaks make the whole piece work much better?

This is an updated version of a story that was previously published. We update our posts as often as possible to ensure they’re useful for our readers.