The Sentence

Writing effective sentences is crucial for writing effective paragraphs. But what makes a sentence effective? Read this lecture on the basic structure of a sentence and complete the practice activities, in which you identify subjects and verbs, revise clauses as complete sentences, and revise sentences to include proper punctuation. Once you complete the practice, check your answers against the Answer Key.

The Sentence

The sentence is the basic unit of writing. A complete sentence must have four things:

  1. a subject
  2. a verb
  3. a complete thought
  4. a period, a question mark, or an exclamation point at its end


The SUBJECT is the person, place, thing, quality, or idea that is doing the action of the clause. It is a noun or a pronoun.

The VERB is the word or words that express the physical or mental action, or condition, of the subject.

We'll start with some different kinds of VERBS; then we'll look at the SUBJECT – who or what is engaged in the action.


A. ACTION VERBS express physical action (hit, run, dance, sing) or mental action (think, know, believe).


Physical Action:

The waves crash against the shore. 

The birds fly above our heads.


Mental Action:

Tim believes in ghosts.

I think Tim is out of his mind.


B. LINKING VERBS do not express action. They help make a statement by linking a subject to a word or idea. They're often associated with a form of the verb "to be": be, am, is, are, was, were, being, and been.

Anton is ready. 

I am leaving.

Verbs like appear, become, feel, grow, look, prove, remain, seem, smell, sound, and taste are linking verbs when they are followed by a word that describes the subject.

You seem tired.

He appears nervous.


C. COMPOUND VERBS AND VERB PHRASES: Sometimes verbs are groups of words.

A compound verb is two or more connected verbs that have the same subject: 

We left at noon and arrived at four.

George washed the windows and mowed the lawn. 

A verb phrase is a group of words that acts as a verb:

The game has been played.

The movie will be coming to a theater near you.


Once you have recognized the VERB, it's easier to locate the SUBJECT. Just ask yourself who or what is performing the action. Subjects are often people or things, but they can also be places, events, qualities, or ideas.


Sarah sang a song.

Who sang? Sarah sang.


Justice is blind.

What is blind? Justice is blind.


My book fell in a puddle. 

What fell? My book fell.


Success feels good.

What feels good? Success feels good.


A. Sometimes the subject may be compound (two or more connected words): 

My aunt and uncle own a bakery.

Who owns? My aunt and uncle.


B. Sometimes the subject may come after the verb:

There is a spider in the sink. 

What is in the sink? A spider.


C. And sometimes the subject may be separated from the verb by several words:

The books on that shelf are old. 

What are old? The books are old.


My cat, startled by the noise, ran under the bed. 

Who ran? My cat ran.


CLAUSES: A clause is any group of words that has both a subject and a verb. There may be other words in a clause, but it must have a subject and a verb. There are two types of clauses: INDEPENDENT and DEPENDENT.


First we'll look at INDEPENDENT CLAUSES.

An Independent Clause contains the first three elements of a sentence: a subject, a verb, and a complete thought. An independent clause can stand on its own as a complete sentence:

College life can be challenging. 

College life can be fun.


These are not only sentences, but they are also independent clauses. Generally, we call them independent clauses when they are combined into one sentence:

College life can be challenging, but it can also be fun. 

Now we have one sentence containing two independent clauses.


Now we'll examine DEPENDENT CLAUSES.

A Dependent Clause is like an independent clause in that it also has a subject and a verb. The difference is that a dependent clause does not express a complete thought:

As cars quickly fill the parking lot 

If we all try to get along

These two clauses each have a subject and a verb, but they do not express complete thoughts. They need something else attached to them in order to make sense. They need an independent clause:

Tension grows as cars quickly fill the parking lot.

If we all try to get along, we can be more productive.

You can see that a dependent clause can never be a sentence by itself. It needs an independent clause to express a complete thought.


PHRASES: A phrase is a group of words that does not have both a subject and a verb. A phrase is only a fragment of a sentence. You've already seen examples of verb phrases:

The game has been played.

The movie will be coming to a theater near you.


Now we'll look at two other kinds of phrases: PREPOSITIONAL PHRASES and VERBAL PHRASES.


First, we'll examine VERBAL PHRASES.

A Verbal Phrase is different from a verb phrase in that it contains either a verb ending with "-ing" or the infinitive form of the verb (to + verb). Verbal Phrases can be used to modify words in a sentence, or they can function as a subject, but they do not function as the verb in a sentence.

This verbal phrase modifies the clause that follows it:

Parking his car a mile off campus, Juan ran to class. 

This phrase functions as the subject of the sentence:

It is inconvenient to walk a mile to campus.



A Prepositional Phrase is a group of words beginning with a preposition. Prepositions are words that tell us the location of or relationship between nouns. Prepositions are words such as at, in, by, of, with, on, up, as, over, under, etc.

Examples of prepositional phrases:

above the desk 

under the desk 

by the desk

in the desk 

beside the desk

Please leave my book on the desk. 

Students with motivation perform well in school. 

The class down the hall is noisy.

In spite of the rain, she made it to class on time.


OBJECTS: Here is one important thing to remember about prepositions: A preposition always has an object – the word or group of words that completes the prepositional phrase.

Please leave my book on the desk.

"On" is the preposition;

"desk" is the object of the preposition;

and the prepositional phrase is "on the desk".


Students with self-motivation perform well in school.

"With" is the preposition;

"self-motivation" is the object of the preposition;

and "with self-motivation" is the prepositional phrase.


The class down the hall is noisy.

"Down" is the preposition;

"hall" is the object of the preposition;

and "down the hall" is the prepositional phrase.


In spite of the rain, she made it to class on time.

"In" and "of" are both prepositions;

"rain" is the object of those prepositions;

and "In spite of the rain" is the prepositional phrase.


PUNCTUATION: Every sentence must end with a period, a question mark or an exclamation point.

A. Period: the most common, it simply indicates the end of the sentence.

B. Question mark: indicates that the sentence is asking a question. The only times this can be confusing is when a sentence is reporting that someone asked a question, rather than asking a direct question itself. If the sentence is reporting, then a period is used:

Watson asked Mary if she would like to join them for dinner. 

Would you like to join us for dinner?

C. Exclamation point: adds emphasis or expresses feeling. Do not overuse, or it will lose its impact.


"Wedlock suits you", he remarked. "I think, Watson, that you have put on seven and a half pounds since I saw you".

"Seven!" I answered.

Watson uses the exclamation point because he is shocked that Holmes thinks he has gained so much weight.


"Let me see!" said Holmes. "Hum! Born in New Jersey in the year 1858. Contralto – hum! La Scala, hum! Prima donna Imperial Opera of Warsaw – yes! Retired from operatic stage – ha! Living in London – quite so!"

By using an exclamation after each statement, no element is given special weight and they all become equally important.


Practice: Subjects/Verbs

For each of the sentences below, identify the subject and the verb, and indicate what kind of verb is used (action, linking, compound, or phrase).

  1. At three o'clock precisely I was at Baker Street.
  2. I fear that I bore you with these details.
  3. He appeared to be in a great hurry.
  4. Slowly and solemnly he was borne into Briony Lodge and laid out in the principal room.
  5. Holmes had sat up upon the couch.
  6. We are but preventing her from injuring another.
  7. A maid rushed across and threw open the window.
  8. Thick clouds of smoke curled through the room. 
  9. He walked swiftly and in silence for some few minutes.
  10. Now it was clear to me that our lady of today had nothing in the house more precious to her than what we are in quest of.


Practice: Complete Thought

Add your own words to each subordinate clause to make it an independent clause (a complete sentence). Hint: first identify the subject and the verb.

  1. The smoke was enough
  2. The coachman had
  3. Because of the hasty retreat he felt
  4. He bowed, and turned away without
  5. And that was how a great scandal threatened


Practice – Punctuation

Fill in each blank with the correct punctuation, either a period, a question mark, or an exclamation point.

  1. "You are sure that she has not sent it yet_______"
  2. "I am sure_______"
  3. "And why_______"
  4. "Because she has said that she would send it on the day when the betrothal was publicly proclaimed, that will be next Monday_______"
  5. "Oh, then we have three days yet_______" exclaimed Holmes.

Source: Washington State Board for Community and Technical Colleges,
Creative Commons License This work is licensed under a Creative Commons Attribution 3.0 License.

Last modified: Friday, January 8, 2021, 1:06 PM