Page 1 Sentence Structure Study Guide for the English Basics

Rules for Writing Sentences Correctly

General Information

“Anyone can write a sentence,” you say. “I’ve been doing that since the first grade!” Certainly, you have! But as you have matured, longer and more complicated sentences have made their way into your communication with others and have been expected from your writing in school. You have moved past all simple sentences and experimented with sentence combining and longer, more complex sentences. With these more advanced sentence types come some very important structural considerations: where to place words so they convey the right meaning, for example. There is a lot to consider as your sentences become longer and more involved. Here are some things to keep in mind.

What Is a Sentence?

A sentence is a group of words that is complete in itself. This means that the group of words contains a subject (who or what the sentence is about), a verb (an action word or state of being), and expresses a complete thought (the reader isn’t left wondering what happened or who it happened to). A sentence can be a statement, form a question, make an exclamation, or give a command. Sentences begin with a capital letter and end with some form of punctuation, either a period (.), question mark (?), or exclamation point (!) depending on their purpose.

Subject and Predicate

To be complete, a sentence must have a subject and a predicate. The subject is usually a noun or pronoun and it indicates who or what the sentence is about. A predicate is the part of a sentence that contains the verb and all of the information about what is being said about the subject. A simple subject is the main noun or pronoun of the sentence. A simple predicate is the verb that describes what the subject is doing. The complete subject includes the simple subject and any modifiers of that subject. The complete predicate is the verb and all modifiers of the verb. Here are some sample sentences with the subject italicized and the predicate (verbs and all modifiers) underlined.

Mary packed a picnic lunch.”
The dog ran on the beach.”
The young, worried parents watched as their child was wheeled into surgery.”
Tired after a long day at work, John went home.”


An object is the noun or pronoun in a sentence that gives meaning to the subject and verb in the sentence. It usually comes after the subject and verb. There are three types of objects: direct objects, indirect objects, and objects of a preposition.

Direct Object

A direct object is the noun or pronoun in a sentence that receives the action of the verb. You can find the direct object by identifying the subject and the verb and then asking Who? or What? in a sentence. For example:

“Daniella and John played tennis on Saturday.”
Subject = Daniella and John
Verb = played
Daniella and John played what? “tennis” = direct object.

“The snake caught a mouse.”
Subject = the snake
Verb = caught
Who or what did the snake catch? “a mouse” = direct object

“Janie loves when her mom makes lasagna for dinner.”
Subject = Janie
Verb = loves
Who or what does Janie love? Janie loves “when her mom makes lasagna for dinner.” This direct object also happens to be a subordinate clause.

“Joe walked his dog for five miles.”
Subject = Joe
Verb = walked
Who or what did Joe walk? “his dog” = direct object
Sometimes the direct object is more than just one or two words.

Only transitive verbs can have direct objects. Transitive verbs are actions that are done to someone or something; they transfer action.

Indirect Object

An indirect object is a noun or pronoun that identifies to whom or for whom the action of the verb is being done. The indirect object is the recipient of the direct object. To find the indirect object, you must first identify the direct object (there cannot be an indirect object without a direct object present), and then ask who or what received it. For example:

“Annika sent her parents a letter from summer camp.”
Subject = Annika
Verb = sent
Who or what did Annika send? “a letter” = direct object
Who received the letter (the direct object)? her parents = indirect object

Here is one more:

“Samuel takes out the garbage for his elderly neighbor.”
Subject = Samuel
Verb = takes
Who or what does Samuel take? “the garbage” = direct object
For whom does Samuel take out the garbage? “his elderly neighbor” = indirect object

Indirect objects are rare and they can only occur if there is also a direct object in the sentence.

Object of a Preposition

The noun or pronoun that follows a preposition is called the object of a preposition. Look at this sentence:

“The cookies on the table are for dad.”
Subject = cookies
Verb = are
Prepositions: on and for. On what? “on the table”, so table is the object of a preposition
For whom are the cookies? “for dad,” so dad is the object of a preposition.

Phrases and Clauses

Phrases and clauses are word groups that work together to form sentences. If we were to look at “layers” of a sentence, the whole is called the sentence. A clause is a group of words that has a subject and a verb. Sometimes clauses can stand on their own as complete sentences (then they are called independent clauses, which we will get to in a moment) and sometimes they must be linked to other clauses to form a complete sentence. The next layer of a sentence is the phrase. A phrase is a group of words that expresses a concept or idea and is used within a clause, which is used to build a sentence. So a phrase is the smallest building block and they are used to create clauses that are used to build sentences.


A phrase is a collection of words working together as a whole but which is missing a subject doing a verb. There may be nouns and verbs present, but there is no subject doing a verb in a phrase. Here are some examples of phrases:

“a rainy afternoon”
“driving in the snow and ice”
“would enjoy some peace and quiet”
“frozen for centuries”
“under the couch”


A clause is a group of words that has a subject and a predicate (a verb). It may or may not be able to stand on its own as a complete sentence. Here are some examples of clauses:

“because we left late”
“when her new dress gets dirty”
“two cats played on the floor”
“Sarah didn’t listen well today”
“while we were at the store”

Independent Clause

An independent clause is a clause that has all the requirements to stand on its own as a sentence: it has a subject, a verb, and expresses a complete thought. Independent clauses may be on their own or they may be linked together to create longer, more varied sentences. Here are some examples of independent clauses:

“waiting for the bus is boring“
“the squirrels are scampering through the trees“
“the birds sing“
“his team won“
“Marco worked all summer to afford his new car“

Dependent Clause

Dependent clauses still have a subject and verb, but they do not make sense by themselves because they do not express a complete thought. They cannot be used alone as complete sentences, they must be linked to an independent clause in order to form a complete sentence. Incomplete or fragment sentences are often the result of dependent clauses trying to pretend to be sentences. Here are some examples of dependent clauses:

“when my sister finally stopped talking”
“that he found for a great price online”
“after I eat breakfast”
“before she brushes her teeth”
“on the way to the train station”

Sentence Fragment

A sentence fragment, also known as an incomplete sentence, is a group of words that is missing one or more of the requirements of a complete sentence: a subject, a verb, and a complete thought. You can identify sentence fragments by looking for those three components and if one is missing, it is a fragment sentence.

Note: Do not judge a sentence by its length. Sentence fragments can occur in seemingly “long” groups of words and short sentences can be complete without having a lot of words. Here are some examples of sentence fragments:

“Went swimming all summer.” (Who went swimming? There is no subject.)

Macy’s cousin, Roxanne, who is afraid of the dark. (What happened with Roxanne? There is no complete thought.)

With no place to go after his parents kicked him out. (Who had no place to go? It’s missing a subject.)

A plot full of twists and turns. (What has a plot full of twists and turns? What does the plot do? This fragment is missing a verb and a complete thought.)

Run-on Sentence

A run-on sentence is a group of words that has too many independent clauses that are not correctly joined together. Run-on sentences contain too many ideas, often without proper punctuation. To join independent clauses together, you must use a comma and a coordinating conjunction or a semicolon. You can generally tell if a sentence is a run-on if you are out of breath by the time you get to the end of it. Like fragment sentences, however, you cannot judge a run-on solely by length. There can be relatively short run-on sentences and not all long sentences are run-ons. Here are some examples of run-on sentences and suggestions for revision:

“Megan likes cats she has five tabbies.”

This is a run-on sentence because it combines two independent clauses without proper punctuation. To fix it, add a semicolon: “Megan likes cats; she has five tabbies.”

“Todd earned ten points in last night’s game, Brian earned thirteen points.”

This is a run-on sentence with a comma splice; that comma is not strong enough to hold two independent clauses together. To fix, add a coordinating conjunction after that comma: “Todd earned ten points in last night’s game, and Brian earned thirteen points.”

“Lonnie said that he would come to the party and Lilly said she would bring the chips and Larry will bring the soda pop but Lisa has to work so she won’t be able to attend.”

Too many ideas! This sentence needs to be broken down into smaller sentences with fewer ideas in each. Here’s a suggestion for revision:

“Lonnie said that he would come to the party. Lilly said she would bring the chips, and Larry will bring the soda pop. Lisa has to work so she won’t be able to attend.”

Sentence Qualities

There are certain aspects all sentences have. These are sentence qualities. Below are some qualities of which to be aware when you are writing your sentences.


There are two “voices” that your writing can take: active voice and passive voice. While both are grammatically acceptable, active voice sentences tend to be more concise, powerful, and effective in delivering a message to an audience. Passive voice lessens the intensity of your message and should rarely be used because it can make sentences wordy and confusing.

Active Voice

In a sentence using active voice, the subject of the sentence actively performs the action or verb in the sentence. This action can take place in the past, present, or future. What makes it an active voice sentence is that the subject had done, is doing, or will do the action directly. Here are some examples of sentences written in active voice:

“The parrot ate the cracker.” (past tense, but the subject parrot did the verb ate)
“Hungry lions roam the savannah.” (present tense, and the subject lions are doing the verb roam)
“The jury will announce the verdict tomorrow.” (future tense, but the subject jury will do the verb announce)

Passive Voice

A sentence is written in passive voice if the intended recipient of the action gets elevated to the status of subject. In passive voice, the subject of the sentence doesn’t do anything, but instead is the recipient of action taken by someone or something else. Using the active voice sentences from the previous section, here is what they would look like rewritten in passive voice:

“The cracker was eaten by the parrot.”
“The savannah is roamed by hungry lions.”
“Tomorrow the verdict will be announced by the jury.”

Grammatically, there is nothing wrong with these sentences. However, they lose some impact and can start to become a little confusing when written in passive voice. Note that all of these passive voice sentences include by, but that is not always the case. For example, “His car has been damaged” is a sentence written in passive voice. To make it active, write: “She damaged his car.”


Diction means word choice. The words you choose to use in sentences is important and every word matters. Choose words that will convey your meaning clearly and concisely. Leave out unnecessary words—longer sentences don’t necessarily mean better sentences.


Syntax is the arrangement of words and phrases to create clear and well-formed sentences. How sentences are structured plays a big part in the reader’s ability to understand and follow them. Clear, easy-to-understand sentences is the goal and how you arrange the words within each sentence (syntax) will create strong, effective sentences.


Sentences should all be about something. In other words, they should have a subject. Subjects are usually nouns or pronouns and identify who or what the sentence is about.