Skip to main content

APUS ePress: Grammar & Punctuation

Welcome to the APUS ePress site - the home of the fully electronic university press for the American Public University System.


From discussion boards to emails to essays, you will write your way through college, especially in an online learning experience. While editing for correctness is expected in all these forms, an understanding of punctuation and grammar can also be a powerful means to help you write exactly what you want to communicate.

Types of Words

Types of words are more precisely known as parts of speech, a grammar term that means the kinds or categories of words. Every word in a language performs a function in a sentence, and these functions are broken down into categories we call:

It is good to know the parts of speech because if you know what the words are doing in a sentence, then you know if the sentence has all of its parts, if you are writing run-ons, using fragments, or if you have sufficient sentence variety - all vitally important to effective writing. You will learn that some words can shift roles. If you are not sure what a word might be, look it up in a dictionary which will list all the forms the word can have.

A person, place, or thing. A noun can also be a concept such as freedom, liberty, or justice.

Writing Application
Knowing how to identify nouns will help you find the subject of a sentence. This will help you determine run-ons, fragments, and passive vs. active voice.


  • Corporation taxes became a political hot potato.
  • Corporations questioned the taxes.
  • Politicians sent the matter to a committee.

Note: Nouns can occur throughout the sentence. A noun can function as the subject of a sentence or as the object of a verb. Do not be distracted by words like "corporate" or "political" which are adjectives. Notice how, in other sentences, "corporations" and "politicians" are nouns. When in doubt, go back to the basic definition of the noun. A noun stands by itself, like "corporation." "Corporate" describes a type of tax (the noun).

A word that conveys action or being/existence.

Writing Application
Every sentence needs a verb, so being able to identify them is essential to avoiding fragments; also, learning to use more powerful verbs transforms writing.


  • Military personnel are ready at all times. (Weak verb)
  • Military personnel stand ready at all times. (Strong verb)
  • Troops had new orders. (weak verb)
  • Troops received and followed new orders. (Strong verbs)

Note: "Be" verbs include: is, are, was, were, be, and being. While these are a necessary part of the English language and you will need to use them, they are weak verbs with little meaning. Look for ways to use stronger verbs as much as possible.


A word that describes a noun or pronoun. The grammar term for this is "modifies." It is important to remember that adjectives can come before or after the noun or pronoun.

Writing Application
Adjectives can be powerful tools to add details, but beware. If writing is overloaded with adjectives, it may be a sign of weak nouns or verbs. It is generally better to convey ideas with strong nouns and verbs rather than layering on adjectives.


  • Corporate taxes became a political hot potato.
  • Troops received and followed new orders.

Note: "Corporate" describes a type of tax. Because "corporate" modifies a noun ("taxes), that makes it an adjective. Additionally, the potato is described as "political" and "hot." "Political" and "hot" both narrow, modify, or change our understanding of what kind of potato this is, so these are adjectives.

  • The expensive restaurant put fancy pink fish on the table. (Weak verb, extra adjectives, wordy sentence)
  • The gourmet bistro served salmon. (Strong verb, one effective adjective, not wordy)

Note: Do not use adjectives when you should be using adverbs. Learn about adverbs below to understand the difference.


A word that describes, or modifies, a verb and is often confused with an adjective. Adverbs are usually identified as "-ly" words.

Writing Application
Adverbs can make verbs more precise or more powerful. Like adjectives, overuse can indicate weak verbs.


  • Police action adversely affected traffic but effectively captured the fugitives.
  • The safety inspection found seating installed incorrectly and incompletely.

Note: A common error is using adjectives instead of adverbs. The way to avoid making this mistake is to know the difference between adjectives and adverbs and their functions in a sentence.

  • Given the adverse weather, authorities cautioned commuters to drive safe and slow. (Incorrect)
  • Given the adverse weather, authorities cautioned commuters to drive safely and slowly. (Correct)
  • Given the adverse weather, authorities recommended a safe and slow drive. (Correct)

Note: In the second sentence the verb is "drive." "Safely" and "slowly" are giving details about the quality of the verb "drive." They are adverbs and require the "-ly" spelling. However, if the word "drive" is used as a noun (as seen in the third sentence above), then the adjectives "safe" and "slow" should be used.

A word that replaces a noun in a sentence.

Writing Application
Pronouns play a significant role in determining the formality of a piece of writing. Different types of writing require particular pronoun usage.


Pronouns also need to be used carefully and correctly. You will want to avoid some common pronoun errors.

Note: Be sure that pronouns agree in number.

  • The officer will report their findings in the next three weeks. (Incorrect. This sentence is trying to avoid sexist language but is committing a grammar error because the subject [officer] is singular and the pronoun is plural [their].)
  • The officer will report his or her findings in the next three weeks. (Correct. Both the subject and the pronouns are singular, and the sentence avoids sexist language.)
  • The officers will report their findings in the next three weeks. (Correct. Both the subject and the pronoun are plural.)

Indefinite Pronouns

In contrast to the pronouns described above (which refer to one or more clear, particular nouns, and are called definite pronouns), indefinite pronouns do not refer to anyone or anything specific.

Writing Application
Some common indefinite pronouns include: anybody, anyone, each, either, everybody, everyone, neither, no one, nobody, other, somebody, and somebody.

In semi-formal writing or in popular media, you might see a sentence like this:


  • Anyone who has attempted to drive across the Metroplex during rush hour will find themselves in a traffic jam. (Incorrect. Anyone = singular. Themselves = plural. Both must be either singular or plural and can't be mixed together.)
  • Anyone who has attempted to drive across the Metroplex during rush hour will find himself or herself in a traffic jam. (Correct, but it sounds awkward.)
  • Those attempting to drive across the Metroplex during rush hour will find themselves in a traffic jam. (Correct. Revised so plural pronouns agree.)
  • Anyone who has attempted to drive across the Metroplex during rush hour will find a traffic jam. (Correct. Revised to eliminate an unnecessary pronoun.)

Note: Most often, the simplest way to make pronouns agree is to revise the text into the plural form. This defaults to "they", "them", and "themselves as the correct pronoun form.


A word that tells where something is in time, space, or direction, and is used with a noun or pronoun to describe nouns, verbs, or adjectives.

Writing Application
Prepositions are vital to convey meaning about location and direction. Be aware that overuse of prepositions causes wordy writing.


  • The computer network was in a room on the third floor behind the employee lunchroom under the gym upstairs. (Wordy!)
  • The computer network was behind the third-floor employee lunchroom. (This is more concise and less wordy.)

Most prepositions can be removed by changing prepositional phrases into an adjective or adverb:

  • The new management of the corporation made decisions concerning the use of old data. (OK, but could be better.)
  • New corporate management made decisions concerning the use of old data. (Eliminating the preposition makes the sentence more concise.)


A word that joins two clauses (sentences) together.

  • Coordinating conjunctions connect two independent clauses and include and, or, but, so, for, yet, and nor.
  • Subordinating conjunctions connect a dependent clause to an independent clause, indicating that one idea is more important than the other. Subordinating conjunctions can include after, although, as, as if, because, before, even, even if, even though, if, if only, in order that, once, provided that, rather than, since, so, supposing, that, though, unless, until, when, where, whereas, wherever, whether, which, and while. For more explanation about clauses, see Types of Sentences below.

Writing Application
Use these words to join sentences together to prevent or to fix a run-on.


  • The Department of Homeland Security handles wide-ranging duties and oversees many agencies including FEMA.
  • Police, fire fighters, paramedics, and other first responders risk their lives, yet they frequently face budget cuts and inadequate compensation.
  • Although most communities respect teaching, they cannot always pay teachers well.
  • The election results became official after all the ballots were counted.


A word used before nouns. Includes two categories: definite ("the") and indefinite ("a/an").

Writing Application
Articles clarify whether the noun is definitely one particular item ("the") or any of that item ("a/an").


  • A lawyer, a skydiver, and comedian Conan O'Brien will be presenting at the awards show. (Here, use of the articles indicates that three different people will be presenting.)
  • Lawyer, skydiver, and comedian Conan O'Brien will be presenting at the awards show. (In this sentence, simply removing the article ["a"] has transformed O'Brien into a lawyer, skydiver, and comedian, and the awards show now has only one presenter.)
  • The building passed inspection and is ready for use. (Here, a specific building is prepared.)
  • A building passed inspection and is ready for use. (In this sentence, any building, we do not know which, is ready.)

Note: While articles may seem like insignificant bits floating around, they convey critical information and can change the meaning of a sentence.

Back to TOP

Subject-Verb Agreement

Subjects and verbs must agree. That means they must match each other in terms of person (first, second, and third) and number (singular or plural). Errors in subject-verb agreement most often occur due to confusion about the subjects of the sentences or the nouns themselves. Misunderstanding the subject, which often means misunderstanding the noun, causes writers to select the incorrect verb form. (See: Types of Words)

Be aware of phrases that come between the subject and verb that may mislead you into choosing the wrong verb. In most cases, the verb needs to be singular, no plural.


  • When "and" joins the sentence, subject, nouns, or pronouns, the sentence needs a plural verb.


  • Washington and Oregon are major wine regions.


  • When "or" joins the sentence subject, the verb agrees with the noun closest to it.


  • Either the professor or the students are documenting the geological site Wednesday.
  • Either the students or the professor is documenting the geological site Wednesday.

Back to TOP

Types of Sentences

While the possibilities for writing are endless, ideas are expressed through four basic sentence types: simple, compound, complex, and compound-complex. If you want to emphasize point, pause, or focus attention while speaking to someone, you know how to do that with your voice. Written language is more formal than the spoken word, but the principle is the same: written language has a voice. One way that voice is conveyed is through sentence variety. If all sentences are the same length and style, the paragraphs will be monotonous, dull, and boring. Sentence variety creates clearer meaning as well as making your writing more interesting to read.

To test for sentence variety, choose a paragraph or two from your writing. Count the word length of each sentence. If all sentences are about the same length, then some editing is in order. Do not fear short sentences or even an occasional longer sentence. The goal is to incorporate variety.




  • The fifty-year period following the Civil War saw considerable change.

This is a simple sentence because it has one subject (the noun period) and one verb (saw). Simple sentences can be long and are not necessarily simplistic. "Simple" refers to the grammar structure of the sentence. This structure of a subject and verb is also called an independent clause because it stands alone.


  • While the fifty-year period following the Civil War saw considerable change, it laid the groundwork for peace and development in the early twentieth century.

This sentence is complex because it has a subject-verb portion (independent clause) that stands alone. Also, it has a subject-verb portion that has been made dependent with the the subordinating conjunction while. When we add while to the independent clause, it can no longer stand alone so it becomes a dependent clause in order to make it a grammatically correct sentence.


  • The fifty-year period following the Civil War saw considerable change and this became known as the age of expansion.

The sentence is a compound sentence because it has two separate subject-verbs combined correctly; or, another way to explain this is that the sentence contains two independent clauses with the coordinating conjunction and. Note the comma before the coordinating conjunction. Using a coordinating conjunction is the grammatically correct way of combining two sentences with a comma. Using other methods can create a comma splice (a type of run-on sentence).

Coordinating conjunctions include and, or, but, so, for, yet, and nor.


  • Because the post-Civil War era saw considerable change, the early twentieth century enjoyed a period of relative prosperity and tranquility, but that was soon shattered.

This sentence is compound-complex because, as the name implies, it has features of both compound and complex sentences. Yes, you can start a sentence with because, but be aware that doing so creates a dependent clause that must be in a sentence with an independent clause. When a dependent clause is punctuated by itself it causes a fragment.

Sentence Types


Back to TOP

Creating Sentence Variety

Creating sentence variety adds rhythm to a paper and distinguishes one writer from another. As you work through your college career, you will find which methods work best for you.

Series and lists

  • Backyard gardening requires a low initial investment: soil enrichment, mulch, raised beds, seeds, hand tools, and some time.
  • Many foods, in moderation, contain healthy fats such as oils, including olive, peanut, soybean, and canola.

Open with adjectives

  • Westward and expansive, the post-Civil War growth provided new opportunities.
  • Exploitative and ruthless, the industrialists took advantage of the period.

Note: It is important not to overuse this strategy.

Open with -ing words

  • Protesting the excess of the industrialists, labor unrest escalated to full-scale movements in the 1800s.
  • Looking back through the past, historians find parallels to current events, yet significant differences as well.

Open with -ly words

  • Fervently, the speaker addressed the audience.
  • Carefully, the investigator pondered over what seemed to be missing.

Back to TOP


Two of the most common types of punctuation you will use in your writing are apostrophes and semicolons. Because you will be using these frequently, it is important to understand how to use them correctly.

Apostrophes have a few specific uses. These are:

  • to make a noun possessive. With singular nouns, you will usually add 's to the end of the noun: "The girl's hair was black." For plural nouns or nouns ending in s, you will only add the apostrophe to the end of the noun: "The two girls' toys were spread all over the floor" or "Achilles' fatal flaw was in his heel."
  • as an indicator of a contraction. For example, could not becomes couldn't or I am becomes I'm. The apostrophe, in these cases, shows that there are absent letters.

Be aware that apostrophes have limitations. Do not use apostrophes to:

  • make a noun plural.
    • Correct: "The Three cats raced into the kitchen."
    • Incorrect: "The three cats' raced into the kitchen."
  • indicate a decade.
    • Correct: "Her favorite era was the 1980s."
    • Incorrect: "Her favorite era was the 1980's."
  • to make words or names ending with numbers plural.
    • Correct: The store sold eight iPhone 3s.
    • Incorrect: The store sold eight iPhone 3's.

Semicolons are a type of punctuation that cause confusion for many beginning writers. Though they can used in a number of different ways, the most common use is as a sort of hard stop similar to a period.  In many instances, a semicolon can be used:

  • in any spot where you could also use a period. The use of semicolons in these cases tends to imply some kind of connection between the two independent clauses being joined. You can often determine if it is appropriate to use a semicolon within a sentence by asking yourself, "Could I place a period here?" If the answer to that question is "No", use a comma instead.

Consider the examples below which illustrate the right way and wrong way to use a semicolon:

  • Correct: "I wanted to go outside for a walk in the sunshine; the flickering lights of the office were depressing."
    • A period could be used between the two sections of this sentence without having any major effect on the meaning.
  • Incorrect: "I wanted to go outside for a walk in the sunshine; because the flickering lights of the office were depressing."
    • The use of the conjunction because in the second half of the sentence makes that second half a dependent clause. This means that it can't stand alone as a sentence. Since a period could not be used here, a semicolon can't be used either.

Apostrophes and semicolons aren't the only options you have to add variety to your writing. The graph below shows examples of additional punctuation techniques which can help enhance your writing.

Back to TOP

Avoiding Run-Ons & Fragments

Run-ons (fused sentences and comma splices) and fragments are portions of writing that violate the rules of proper punctuation. The problem is, improperly punctuated sentences are confusing. Punctuation and grammar rules help make meaning clearer.

The first step to understanding run-ons and fragments is to understand sentence structure and the roles of words. (See: Types of Words, Types of Sentences, and Creating Sentence Variety)



APUS Students are located all over the world, many are deployed in the military, and some work for private companies.


This is a comma splice run-on because two sentences have been punctuated as one sentence.

APUS students are located all over the world. Many are deployed in the military, and some work for private companies.


Inserting a period is the quickest fix, but it may produce the weakest sentences, especially if the paragraph overall lacks variety.

APUS students are located all over the world; many are deployed in the military, and some work for private companies.


Inserting a semi-colon is also a quick fix and adds a little sentence variety; it may be a good option, or there may be better options.

APUS students, located all over the world, are deployed in the military or work for private companies.


Revision work makes the sentence more interesting.

Deployed in the military or working for private companies, APUS students are located all over the world.


This takes the previous revision and reverses the sentence order making it even more interesting and adding more variety.

She thought the library database had no sources on her topic however, when she changed the search terms, she found 422 articles.


This is a fused run-on sentence.

She thought the library database had no sources on her topic; however, when she changed the search terms, she found 422 articles.


The semi-colon helps break the sentence up to avoid a run-on or fragment.

Take Note

Back to TOP