Sentence Structure

Introduction

Learning Objectives

  • Evaluate common sentence structures
  • Evaluate sentence punctuation patterns
  • Identify and revise run-on sentences
  • Identify and revise sentence fragments
  • Evaluate and employ parallel structure

It’s important to have variety in your sentence length and structure. This quote from Gary Provost illustrates why:

This sentence has five words. Here are five more words. Five-word sentences are fine. But several together become monotonous. Listen to what is happening. The writing is getting boring. The sound of it drones. It’s like a stuck record. The ear demands some variety. Now listen. I vary the sentence length, and I create music. Music. The writing sings. It has a pleasant rhythm, a lilt, a harmony. I use short sentences. And I use sentences of medium length. And sometimes when I am certain the reader is rested, I will engage him with a sentence of considerable length, a sentence that burns with energy and builds with all the impetus of a crescendo, the roll of the drums, the crash of the cymbals–sounds that say listen to this, it is important.

So write with a combination of short, medium, and long sentences. Create a sound that pleases the reader’s ear. Don’t just write words. Write music.[1]

You can also listen to the difference in the video below:

In order to create this variety, you need to know how sentences work and how to create them. In this outcome we will identify the parts of sentences and learn how they fit together to create music in writing.


Basic Parts of a Sentence

Every sentence has a subject and a predicate. The subject of a sentence is the noun, pronoun, or phrase or clause the sentence is about:

  • Einstein’s general theory of relativity has been subjected to many tests of validity over the years.
  • Although a majority of caffeine drinkers think of it as a stimulant, heavy users of caffeine say the substance relaxes them.
  • In a secure landfill, the soil on top and the cover block storm water intrusion into the landfill. (compound subject)

The predicate is the rest of the sentence after the subject:

  • The pressure in a pressured water reactor varies from system to system.
  • The pressure is maintained at about 2250 pounds per square inch to prevent steam from forming.
  • The pressure is then lowered to form steam at about 600 pounds per square inch.
  • In contrast, a boiling water reactor operates at constant pressure.

A predicate can include the verb, a direct object, and an indirect object.

Direct Object

A direct object—a noun, pronoun, phrase, or clause acting as a noun—takes the action of the main verb. A direct object can be identified by putting what?, which?, or whom? in its place.

  • The housing assembly of a mechanical pencil contains the mechanical workings of the pencil.
    • The action (contains) is directly happening to the object (workings).
  • Lavoisier used curved glass discs fastened together at their rims, with wine filling the space between, to focus the sun’s rays to attain temperatures of 3000° F.
    • The action (used) is directly happening to the object (discs).
  • A 20 percent fluctuation in average global temperature could reduce biological activity, shift weather patterns, and ruin agriculture(compound direct object)
    • The actions are directly happening to multiple objects: reduce activityshift patterns, and ruin agriculture.
  • On Mariners 6 and 7, the two-axis scan platforms provided much more capability and flexibility for the scientific payload than those of Mariner 4. (compound direct object)
    • The action (provided) is directly happening to multiple objects (capability and flexibility).

Indirect Object

An indirect object—a noun, pronoun, phrase, or clause acting as a noun—receives the action expressed in the sentence. It can be identified by inserting to or for.

  • The company is designing senior citizens a new walkway to the park area.
    • The company is not designing new models of senior citizens; they are designing a new walkway for senior citizens. Thus, senior citizens is the indirect object of this sentence.
    • Walkway is the direct object of this sentence, since it is the thing being designed.
  • Please send the personnel office a resume so we can further review your candidacy.
    • You are not being asked to send the office somewhere; you’re being asked to send a resume to the office. Thus, the personnel office is the indirect object of this sentence.
    • Resume is the direct object of this sentence, since it is the thing you should send.

Phrases and Clauses

Phrases and clauses are groups of words that act as a unit and perform a single function within a sentence. A phrase may have a partial subject or verb but not both; a dependent clause has both a subject and a verb (but is not a complete sentence). Here are a few examples (not all phrases are highlighted because some are embedded in others):

Phrases Clauses
Electricity has to do with those physical phenomena involving electrical charges and their effects when in motion and when at rest.(involving electrical charges and their effects is also a phrase.) Electricity manifests itself as a force of attraction, independent of gravitational and short-range nuclear attraction, when two oppositely charged bodies are brought close to one another.
In 1833, Faraday’s experimentation with electrolysis indicated a natural unit of electrical charge, thus pointing to a discrete rather than continuous charge. (to a discrete rather than continuous charge is also a phrase.) Since the frequency is the speed of sound divided by the wavelength, a shorter wavelength means a higher wavelength.
The symbol that denotes a connection to the grounding conductor is three parallel horizontal lines, each of the lower ones being shorter than the one above it. Nuclear units planned or in construction have a total capacity of 186,998 KW, which, if current plans hold, will bring nuclear capacity to about 22% of all electrical capacity by 1995. (if current plans hold is a clause within a clause)

There are two types of clauses: dependent and independent. A dependent clauses is dependent on something else: it cannot stand on its own. An independent clause, on the other hand, is free to stand by itself.

So how can you tell if a clause is dependent or independent? Let’s take a look at the clauses from the table above:

  • when two oppositely charged bodies are brought close to one another
  • Since the frequency is the speed of sound divided by the wavelength
  • which, if current plans hold, will bring nuclear capacity to about 22% of all electrical capacity by 1995

All of these clauses are dependent clauses. We can tell because of the words whensince, and which. Words like sincewhen, and because turn an independent clause into a dependent clause. For example “I was a little girl in 1995” is an independent clause, but “Because I was a little girl in 1995” is a dependent clause. This class of word includes the following:

after although as as far as as if as long as as soon as
as though because before even if even though every time if
in order that since so so that than though unless
until when whenever where whereas wherever  while

Common Sentence Structures

Basic Sentence Patterns

Subject + verb

The simplest of sentence patterns is composed of a subject and verb without a direct object or subject complement. It uses an intransitive verb, that is, a verb requiring no direct object:

  • Control rods remain inside the fuel assembly of the reactor.
  • The development of wind power practically ceased until the early 1970s.
  • The cross-member exposed to abnormal stress eventually broke.
  • Only two types of charge exist in nature.

Subject + verb + direct object

Another common sentence pattern uses the direct object:

  • Silicon conducts electricity in an unusual way.
  • The anti-reflective coating on the the silicon cell reduces reflection from 32 to 22 percent.

Subject + verb + indirect object + direct object

The sentence pattern with the indirect object and direct object is similar to the preceding pattern:

  • I am writing her about a number of problems that I have had with my computer.
  • Austin, Texas, has recently built its citizens a system of bike lanes.

Sentence Types

Simple Sentences

A simple sentence is one that contains a subject and a verb and no other independent or dependent clause.

  • One of the tubes is attached to the manometer part of the instrument indicating the pressure of the air within the cuff.
  • There are basically two types of stethoscopes.
    • In this sentence, the subject and verb are inverted; that is, the verb comes before the subject. However, it is still classified as a simple sentence.
  • To measure blood pressure, a sphygmomanometer and a stethoscope are needed.
    • This sentence has a compound subject—that is, there are two subjects—but it is still classified as a simple sentence.

Command sentences are a subtype of simple sentences. These sentences are unique because they don’t actually have a subject:

  • Clean the dishes.
  • Make sure to take good notes today.
  • After completing the reading, answer the following questions.

In each of these sentences, there is an implied subject: you. These sentences are instructing the reader to complete a task. Command sentences are the only sentences in English that are complete without a subject.

Compound Predicates

A predicate is everything in the verb part of the sentence after the subject (unless the sentence uses inverted word order). A compound predicate is two or more predicates joined by a coordinating conjunction. Traditionally, the conjunction in a sentence consisting of just two compound predicates is not punctuated.

  • Another library media specialist has been using Accelerated Reader for ten years and has seen great results.
  • This cell phone app lets users share pictures instantly with followers and categorize photos with hashtags.

Compound Sentences

A compound sentence is made up of two or more independent clauses joined by a coordinating conjunction (and, or, nor, but, yet, for) and a comma, an adverbial conjunction and a semicolon, or just a semicolon.

  • In sphygmomanometers, too narrow a cuff can result in erroneously high readings, and too wide a cuff can result in erroneously low readings.
  • Some cuff hook together; others wrap or snap into place.

Sentence Punctuation Patterns

While there are infinite possibilities for sentence construction, let’s take a look at some of the most common punctuation patterns in sentences. In order to do this, let’s first look at this passage about Queen Elizabeth I. You don’t need to pay attention to the words: just look at the punctuation.

a painting of queen elizabeth the first.

The “Darnley Portrait” of Elizabeth I of England

Elizabeth I was Queen of England and Ireland from 17 November 1558 until her death on March 24, 1603. Elizabeth was the daughter of Henry VIII and Anne Boleyn, his second wife, who was executed two and a half years after Elizabeth’s birth. Sometimes called The Virgin Queen, the childless Elizabeth was the fifth and last monarch of the Tudor dynasty.

Elizabeth’s reign is known as the Elizabethan era. The period is famous for the flourishing of English drama, led by playwrights (such as William Shakespeare and Christopher Marlowe) and for the seafaring prowess of English adventurers (such as Francis Drake). Towards the end of her reign, a series of economic and military problems weakened her popularity. Elizabeth is acknowledged as a charismatic performer and a dogged survivor in an era when government was ramshackle and limited, and when monarchs in neighboring countries faced internal problems that jeopardized their thrones. After the short reigns of Elizabeth’s half-siblings, her 44 years on the throne provided welcome stability for the kingdom and helped forge a sense of national identity.

Now let’s look at the passage with the words removed:

____________________________________________________________________, ____. ____________________________, __________, ______________________________________. _________________, ___________________________________________________.

__________________________________. ________________________________________, ___________ (____________________________________) ____________________________________ (________________). ________________, _______________________________________________. _________________________________________________________________________________, __________________________________________________________________. ________________________, __________________________________________________.

As you can see, this passage has a fairly simple punctuation structure. It simply uses periods, commas, and parentheses. These three marks are the most common punctuation you will see. Some other common sentence patterns include the following:

  • ________; ________.
    • Elizabeth was baptized on 10 September; Archbishop Thomas Cranmer stood as one of her godparents.
  • ________; however, ________.
    • The English took the defeat of the armada as a symbol of God’s favor; however, this victory was not a turning point in the war.
  • ________: ____, ____, and ____.
    • The period is famous for the flourishing of English drama, led by several well-known playwrights: William Shakespeare, Christopher Marlowe, and Francis Beaumont.

Run-on Sentences

run-on sentence is a sentence that goes on and on and needs to be broken up. Run-on sentences occur when two or more independent clauses are improperly joined. (We talked about clauses in Text: Parts of a Sentence.) One type of run-on that you’ve probably heard of is the comma splice, in which two independent clauses are joined by a comma without a coordinating conjunction (and, orbut, etc.).

Let’s look at a few examples of run-on sentences:

  • Often, choosing a topic for a paper is the hardest part it’s a lot easier after that.
  • Sometimes, books do not have the most complete information, it is a good idea then to look for articles in specialized periodicals.
  • She loves skiing but he doesn’t.

All three of these have two independent clauses. Each clause should be separated from another with a period, a semicolon, or a comma and a coordinating conjunction:

  • Often, choosing a topic for a paper is the hardest part. It’s a lot easier after that.
  • Sometimes, books do not have the most complete information; it is a good idea then to look for articles in specialized periodicals.
  • She loves skiing, but he doesn’t.

Common Causes of Run-Ons

We often write run-on sentences because we sense that the sentences involved are closely related and dividing them with a period just doesn’t seem right. We may also write them because the parts seem to short to need any division, like in “She loves skiing but he doesn’t.” However, “She loves skiing” and “he doesn’t” are both independent clauses, so they need to be divided by a comma and a coordinating conjunction—not just a coordinating conjunction by itself.

Another common cause of run-on sentences is mistaking adverbial conjunctions for coordinating conjunctions. For example if we were to write, “She loved skiing, however he didn’t,” we would have produced a comma splice. The correct sentence would be “She loved skiing; however, he didn’t.”

Fixing Run-On Sentences

Before you can fix a run-on sentence, you’ll need to identify the problem. When you write, carefully look at each part of every sentence. Are the parts independent clauses, or are they dependent clauses or phrases? Remember, only independent clauses can stand on their own. This also means they have to stand on their own; they can’t run together without correct punctuation.

Let’s take a look at a few run-on sentences and their revisions:

  1. Most of the hours I’ve earned toward my associate’s degree do not transfer, however, I do have at least some hours the University will accept.
  2. The opposite is true of stronger types of stainless steel they tend to be more susceptible to rust.
  3. Some people were highly educated professionals, others were from small villages in underdeveloped countries.

Let’s start with the first sentence. This is a comma-splice sentence. The adverbial conjunction however is being treated like a coordinating conjunction. There are two easy fixes to this problem. The first is to turn the comma before however into a period. If this feels like too hard of a stop between ideas, you can change the comma into a semicolon instead.

  • Most of the hours I’ve earned toward my associate’s degree do not transfer. However, I do have at least some hours the University will accept.
  • Most of the hours I’ve earned toward my associate’s degree do not transfer; however, I do have at least some hours the University will accept.

The second sentence is a run-on as well. “The opposite is true of stronger types of stainless steel” and “they tend to be more susceptible to rust.” are both independent clauses. The two clauses are very closely related, and the second clarifies the information provided in the first. The best solution is to insert a colon between the two clauses:

The opposite is true of stronger types of stainless steel: they tend to be more susceptible to rust.

What about the last example? Once again we have two independent clauses. The two clauses provide contrasting information. Adding a conjunction could help the reader move from one kind of information to another. However, you may want that sharp contrast. Here are two revision options:

  • Some people were highly educated professionals, while others were from small villages in underdeveloped countries.
  • Some people were highly educated professionals. Others were from small villages in underdeveloped countries.

Sentence Fragments

Fragments are simply grammatically incomplete sentences—they are phrases and dependent clauses. We talked about phrases and clauses a bit in the section “Basic Parts of a Sentence” above. These are grammatical structures that cannot stand on their own: they need to be connected to an independent clause to work in writing. So how can we tell the difference between a sentence and a sentence fragment? And how can we fix fragments when they already exist?

Common Causes of Fragments

Part of the reason we write in fragments is because we often speak that way. However, there is a difference between writing and speech, and it is important to write in full sentences. Additionally, fragments often come about in writing because a fragment may already seem too long.

Non-finite verbs (gerunds, participles, and infinitives) can often trip people up as well. Since non-finite verbs don’t act like verbs, we don’t count them as verbs when we’re deciding if we have a phrase or a clause. Let’s look at a few examples of these:

  • Running away from my mother.
  • To ensure your safety and security.
  • Beaten down since day one.

Even though all of the above have non-finite verbs, they’re phrases, not clauses. In order for these to be clauses, they would need an additional verb that acts as a verb in the sentence.

Words like sincewhen, and because turn an independent clause into a dependent clause. For example “I was a little girl in 1995” is an independent clause, but “Because I was a little girl in 1995” is a dependent clause. This class of word includes the following:

after although as as far as as if as long as as soon as
as though because before even if even though every time if
in order that since so so that than though unless
until when whenever where whereas wherever  while

The words that and which do the same type of thing as those listed above.

Coordinating conjunctions (our FANBOYS) can also cause problems. If you start a sentence with a coordinating conjunction, make sure that it is followed a complete clause, not just a phrase!

Fixing Sentence Fragments

Let’s take a look at a couple of examples:

  1. Ivana appeared at the committee meeting last week. And made a convincing presentation of her ideas about the new product.
  2. The committee considered her ideas for a new marketing strategy quite powerful. The best ideas that they had heard in years.
  3. She spent a full month evaluating his computer-based instructional materials. Which she eventually sent to her supervisor with the strongest of recommendations.

Let’s look at the phrase “And made a convincing presentation of her ideas about the new product” in example one. It’s just that: a phrase. There is no subject in this phrase, so the easiest fix is to simply delete the period and combine the two statements:

Ivana appeared at the committee meeting last week and made a convincing presentation of her ideas about the new product.

Let’s look at example two. The phrase “the best ideas they had heard in years” is simply a phrase—there is no verb contained in the phrase. By adding “they were” to the beginning of this phrase, we have turned the fragment into an independent clause, which can now stand on its own:

The committee considered her ideas for a new marketing strategy quite powerful; they were the best ideas that they had heard in years.

What about example three? Let’s look at the clause “Which she eventually sent to her supervisor with the strongest of recommendations.” This is a dependent clause; the word which signals this fact. If we change “which she eventually” to “eventually, she,” we also turn the dependent clause into an independent clause.

She spent a full month evaluating his computer-based instructional materials. Eventually, she sent the evaluation to her supervisor with the strongest of recommendations.

Parallel Structure

What exactly is parallel structure? It’s simply the practice of using the same structures or forms multiple times: making sure the parts are parallel to each other. Parallel structure can be applied to a single sentence, a paragraph, or even multiple paragraphs. Compare the two following sentences:

  • Yara loves running, to swim, and biking.
  • Yara loves running, swimming, and biking.

Was the second sentence easier to comprehend than the first? The second sentence uses parallelism—all three verbs are gerunds, whereas in the first sentence two are gerunds and one is an infinitive. While the first sentence is technically correct, it’s easy to trip up over the mismatching items. The application of parallelism improves writing style and readability, and it makes sentences easier to process.

Compare the following examples:

  • Lacking parallelism: “She likes cooking, jogging, and to read.”
    • Parallel: “She likes cooking, jogging, and reading.”
    • Parallel: “She likes to cook, jog, and read.”
  • Lacking parallelism: “He likes to swim and running.”
    • Parallel: “He likes to swim and to run.”
    • Parallel: “He likes swimming and running.”

Once again, the examples above combine gerunds and infinitives. To make them parallel, the sentences should be rewritten with just gerunds or just infinitives. Note that the first nonparallel example, while inelegantly worded, is grammatically correct: “cooking,” “jogging,” and “to read” are all grammatically valid conclusions to “She likes.”

  • Lacking parallelism: “The dog ran across the yard, jumped over the fence, and down the alley sprinted.”
  • Grammatical but not employing parallelism: “The dog ran across the yard and jumped over the fence, and down the alley he sprinted.”
  • Parallel: “The dog ran across the yard, jumped over the fence, and sprinted down the alley.”

The nonparallel example above is not grammatically correct: “down the alley sprinted” is not a grammatically valid conclusion to “The dog.” The second example, which does not attempt to employ parallelism in its conclusion, is grammatically valid; “down the alley he sprinted” is an entirely separate clause.

Rhetoric and Parallelism

Parallelism can also involve repeated words or repeated phrases. These uses are part of “rhetoric” (a field that focuses on persuading readers) Here are a few examples of repetition:

  • The inherent vice of capitalism is the unequal sharing of blessings; the inherent virtue of socialism is the equal sharing of miseries.” —Winston Churchill
  • “Let every nation know, whether it wishes us well or ill, that we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe to assure the survival and the success of liberty.” —John F. Kennedy
  • “And that government of the people, by the people, for the people, shall not perish from the earth.” —Abraham Lincoln, Gettysburg Address

When used this way, parallelism makes your writing or speaking much stronger. These repeated phrases seem to bind the work together and make it more powerful—and more inspiring.


Self-Check


  1. Provost, Gary. 100 Ways to Improve Your Writing, Signet:1985, pp. 60–61.