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3.1: Sentence Writing

Skills to Develop

  • Identify the components of a basic sentence
  • Identify the four most serious writing errors

Before we work more on piecing ideas together to form summaries and paragraphs, we need to look at fundamental sentence construction. Imagine you are reading a book for school. You need to find important details that you can use for an assignment. However, when you begin to read, you notice that the book has very little punctuation. The sentences fail to form complete paragraphs and instead form one block of text without clear organization. Most likely, this book would frustrate and confuse you. Without clear and concise sentences, it is difficult to find the information you need.

For both students and professionals, clear communication is important. Whether you are typing an email or writing a report or essay, it is your responsibility as the writer to present your thoughts and ideas clearly and precisely. Writing in complete sentences is one way to ensure that you communicate well. This section covers how to recognize and write basic sentence structures and how to avoid some common writing errors.

Components of a Sentence

Clearly written, complete sentences require key information: a subject, a verb and a complete idea. A sentence needs to make sense on its own. Sometimes, complete sentences are also called independent clauses. A clause is a group of words that may make up a sentence. An independent clause is a group of words that may stand alone as a complete, grammatically correct thought. The following sentences show independent clauses.


All complete sentences have at least one independent clause. You can identify an independent clause by reading it on its own and looking for the subject and the verb.


When you read a sentence, you may first look for the subject or what the sentence is about. The subject usually appears at the beginning of a sentence as a noun or a pronoun. A noun is a word that identifies a person, place, thing, or idea. A pronoun is a word that replaces a noun. Common pronouns are I, he, she, it, you, they, and we. In the following sentences, the subject is underlined once.

Malik is the project manager for this project. He will give us our assignments.

In these sentences, the subject is a person: Malik. The pronoun He replaces and refers back to Malik.


In the first sentence, the subject is a place: computer lab. In the second sentence, the pronoun It substitutes for computer lab as the subject.


In the first sentence, the subject is a thing: project. In the second sentence, the pronoun It stands in for the project.


In this chapter, please refer to the following grammar key:


Compound Subjects

A sentence may have more than one person, place, or thing as the subject. These subjects are called compound subjects. Compound subjects are useful when you want to discuss several subjects at once.


Prepositional Phrases

You will often read a sentence that has more than one noun or pronoun in it. You may encounter a group of words that includes a preposition with a noun or a pronoun. Prepositions connect a noun, pronoun, or verb to another word that describes or modifies that noun, pronoun, or verb. Common prepositions include in, on, under, near, by, with, and about. A group of words that begin with a preposition is called a prepositional phrase. A prepositional phrase begins with a preposition and modifies or describes a word. It cannot act as the subject of a sentence. The following circled phrases are examples of prepositional phrases.


Exercise 3.1

Read the following sentences. Underline the subjects and circle the prepositional phrases.

The gym is open until nine o’clock tonight.
The student with the most extra credit will win a homework pass.
Maya and Tia found an abandoned cat by the side of the road.
The driver of that pickup truck skidded on the ice.
Anita won the race with time to spare.
The people who work for that company were surprised about the merger.
Working in haste means that you are more likely to make mistakes.
The soundtrack has over 60 songs in languages from around the world.
His latest invention does not work, but it has inspired the rest of us.


Once you locate the subject of a sentence, you can move on to the next part of a complete sentence: the verb. A verb is often an action word that shows what the subject is doing. A verb can also link the subject to a describing word. There are three types of verbs that you can use in a sentence: action verbs, linking verbs, or helping verbs.

Action Verbs

A verb that connects the subject to an action is called an action verb. An action verb answers the question what is the subject doing? In the following sentences, the words underlined twice are action verbs.


Linking Verbs

A verb can often connect the subject of the sentence to a describing word. This type of verb is called a linking verb because it links the subject to a describing word. In the following sentences, the words underlined twice are linking verbs.


If you have trouble telling the difference between action verbs and linking verbs, remember:

An action verb shows that the subject is doing something.

A linking verb simply connects the subject to another word that describes or modifies the subject.

A few verbs can be used as either action verbs or linking verbs.


Although both sentences use the same verb, the two sentences have completely different meanings. In the first sentence, the verb describes the boy’s action. In the second sentence, the verb describes the boy’s appearance.

Helping Verbs

A third type of verb you may use as you write is a helping verb. Helping verbs are verbs that are used with the main verb to describe a mood or tense. Helping verbs are usually a form of be, do, or have. The word can is also used as a helping verb.



Whenever you write or edit sentences, keep the subject and verb in mind. As you write, ask yourself these questions to keep yourself on track:

Subject: Who or what is the sentence about?

Verb: Which word shows an action or links the subject to a description?

Exercise 3.2

Underline the verb(s) in each of the sentences below twice. Name the type of verb(s) used in the sentence in the space provided (LV, HV, or V).

The cat sounds ready to come back inside. ________
We have not eaten dinner yet. ________
It took four people to move the broken down car. ________
The book was filled with notes from class. ________
We walked from room to room, inspecting for damages. ________
Harold was expecting a package in the mail. ________
The clothes still felt damp even though they had been through the dryer twice. ________
The teacher who runs the studio is often praised for his restoration work on old masterpieces. ________

Sentence Structure (Including Fragments)

Now that you know what makes a complete sentence—a subject and a verb—you can use other parts of speech to build on this basic structure. Good writers use a variety of sentence structures to make their work more interesting. This section covers different sentence structures that you can use to make longer, more complex sentences.

Sentence Patterns

Six basic subject-verb patterns can enhance your writing. A sample sentence is provided for each pattern. As you read each sentence, take note of where each part of the sentence falls. Notice that some sentence patterns use action verbs and others use linking verbs.

Subject ——> Verb


Subject —–> Linking Verb ——> Noun


Subject —–> Linking Verb ——> Adjective


Subject —–> Verb ——> Adverb


Subject —–> Verb ——> Direct Object


When you write a sentence with a direct object (DO), make sure that the DO receives the action of the verb.

Subject —–> Verb ——> Indirect Object ——> Direct Object


In this sentence structure, an indirect object explains to whom or to what the action is being done. The indirect object is a noun or pronoun, and it comes before the direct object in a sentence.

Exercise 3.3

Use what you have learned so far to bring variety in your writing. Use the following lines or your own sheet of paper to write six sentences that practise each basic sentence pattern. When you have finished, label each part of the sentence (S, V, LV, N, Adj, Adv, DO, IO).




CollaborationFind an article in a newspaper, a magazine, or online that interests you. Then, identify one example of each part of a sentence (S, V, LV, N, Adj, Adv, DO, IO).


The sentences you have encountered so far have been independent clauses. As you look more closely at your past writing assignments, you may notice that some of your sentences are not complete. A sentence that is missing a subject or a verb is called a fragment. A fragment may include a description or may express part of an idea, but it does not express a complete thought.

Fragment: Children helping in the kitchen.

Complete sentence: Children helping in the kitchen often make a mess.

You can easily fix a fragment by adding the missing subject or verb. In the example, the sentence was missing a verb. Adding often make a mess creates an S-V-N sentence structure. Figure 3.1 illustrates how you can edit a fragment to become a complete sentence.


Figure 3.1 - Editing Fragments That Are Missing a Subject or a Verb 

See whether you can identify what is missing in the following fragments.

Fragment: Told her about the broken vase.
Complete sentence: I told her about the broken vase.
Complete sentence: The store down on Main Street sells music.

Common Sentence Errors

Fragments often occur because of some common errors, such as starting a sentence with a preposition, a dependent word, an infinitive, or a gerund. If you use the six basic sentence patterns when you write, you should be able to avoid these errors and thus avoid writing fragments.

When you see a preposition, check to see that it is part of a sentence containing a subject and a verb. If it is not connected to a complete sentence, it is a fragment, and you will need to fix this type of fragment by combining it with another sentence. You can add the prepositional phrase to the end of the sentence. If you add it to the beginning of the other sentence, insert a comma after the prepositional phrase. Look at the examples. Figure 3.2 illustrates how you can edit a fragment that begins with a preposition.

Example \(\PageIndex{1}\):

Example A


Example B



Figure 3.2 - Editing Fragments That Begin with a Preposition

 Clauses that start with a dependent word—such as since, because, without, or unless—are similar to prepositional phrases. Like prepositional phrases, these clauses can be fragments if they are not connected to an independent clause containing a subject and a verb. To fix the problem, you can add such a fragment to the beginning or end of a sentence. If the fragment is added at the beginning of a sentence, add a comma after it before the independent clause.



When you encounter a word ending in -ing in a sentence, identify whether it is being used as a verb in the sentence. You may also look for a helping verb. If the word is not used as a verb or if no helping verb is used with the -ing verb form, the verb is being used as a noun. An -ing verb form used as a noun is called a gerund.


Once you know whether the -ing word is acting as a noun or a verb, look at the rest of the sentence. Does the entire sentence make sense on its own? If not, what you are looking at is a fragment. You will need to either add the parts of speech that are missing or combine the fragment with a nearby sentence. Figure 3.3 illustrates how to edit fragments that begin with a gerund.


Figure 3.3 - Editing Fragments That Begin with Gerunds

Incorrect: Taking deep breaths. Saul prepared for his presentation.

Correct: Taking deep breaths, Saul prepared for his presentation.

Correct: Saul prepared for his presentation. He was taking deep breaths.

Incorrect: Congratulating the entire team. Sarah raised her glass to toast their success.

Correct: She was congratulating the entire team. Sarah raised her glass to toast their success.

Correct: Congratulating the entire team, Sarah raised her glass to toast their success.

Another error in sentence construction is a fragment that begins with an infinitive. An infinitive is a verb paired with the word to; for example, to run, to write, or to reach. Although infinitives are verbs, they can be used as nouns, adjectives, or adverbs. You can correct a fragment that begins with an infinitive by either combining it with another sentence or adding the parts of speech that are missing.

Incorrect: We needed to make 300 more paper cranes. To reach the one thousand mark.

Correct: We needed to make 300 more paper cranes to reach the one thousand mark.

Correct: We needed to make 300 more paper cranes. We wanted to reach the one thousand mark.

Exercise 3.4

Copy the following sentences onto your own sheet of paper and circle the fragments. Then combine the fragment with the independent clause to create a complete sentence.

Working without taking a break. We try to get as much work done as we can in an hour.
I needed to bring work home. In order to meet the deadline.
Unless the ground thaws before spring break. We won’t be planting any tulips this year.
You’ll find what you need if you look. On the shelf next to the potted plant.
To find the perfect apartment. Deidre scoured the classifieds each day.

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