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11.1: Punctuation

Difficulty Level: At Grade Created by: CK-12
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Lesson Objectives

  • Use commas with coordinating conjunctions, subordinating conjunctions, and introductory phrases.
  • Use semicolons to connect independent clauses.
  • Use colons to introduce lists.
  • Use hyphens with modifiers.
  • Indicate possession with singular and plural nouns using apostrophes.
  • Emphasize with dashes and de-emphasize with parentheses.


Use commas with coordinating conjunctions that join two independent clauses. There are seven coordinating conjunctions: for, and, but, or, yet, and so. Using the acronym FANBOYS will help you remember them.

For a definition and examples of independent and dependent clauses, see Chapter 12, Lesson 1.

You should only connect two independent clauses per sentence. Long strings of independent clauses are usually considered run-on sentences.

Example 1 - Tell me what you eat, and I will tell you what you are.

The coordinating conjunction “and” is connecting two independent clauses. Notice that in the first clause, the subject is a missing but implied “you.” We still consider clauses with an implied “you” (what we term imperative statements) to be independent.

Example 2 - I looked all over the house, but I couldn’t find my keys.

The coordinating conjunction “but” is connecting two independent clauses. Since the subject “I” is restated in the second clause, we consider it a separate subject.

Example 3 - Ms. Brenner went to the local police station and disputed her speeding ticket with the officer at the front desk.

Notice that the coordinating conjunction “and” is connecting two nouns (“went” and “disputed”) instead of two independent clauses. Do not use commas when connecting two verbs, adjectives, or nouns unless you want to place special emphasis on the second item.

Use the comma to separate three or more elements in a series. Although you are not absolutely required to place a comma before the last item in a series, it seems to be a general academic convention to include. Whether you decide to use it or not, make sure to keep it consistent throughout your writing.

Example 1 - During her trip to Europe, Erica visited Sweden, Norway, Denmark, and Holland.

Use a comma after a dependent clause when it comes before an independent clause. Use a comma with a dependent clause that comes after an independent clause only if the subordinating conjunction implies contrast (i.e. though, whereas).

Example 1 - If you speak the truth, have a foot in the stirrup.

The subordinating conjunction “if” marks the dependent clause as coming before the independent clause. Place a comma between the ending of the dependent clause and the beginning of the independent clause.

Example 2 - He cancelled his magazine subscription because he thought the editors no longer addressed important issues.

The subordinating conjunction “because” does not imply a contrast between the independent clause and the dependent clause. Therefore, we do not use a comma before “because.”

Example 3 - Allen is scrambling to finish all of his projects, whereas Amy planned ahead and had everything finished by last Thursday.

The subordinating conjunction “whereas” implies a contrast between the independent clause and the dependent clause.

Many sentences begin with a prepositional, gerund, or infinitive phrase that introduces or explains the sentence. Place a comma between the end of the introductory phrase and the beginning of the subject. If the introductory phrase is less than four words long, you often do not need to use a comma, although it is never wrong to use one to be safe.

For definitions and examples of phrases, see Chapter 12, Lesson 2.

Example 1 - To get a good grade, you must complete all of your assignments.

The sentence is introduced with an infinitive phrase, and the comma is placed before the subject “you.”

Example 2 - Justifying a fault doubles it.

Notice that the gerund phrase is not working as an introductory phrase, but as the subject itself. If a phrase is filling the role of sentence subject, then we do not place a comma after it.

Review Questions

For each example sentence, insert missing commas or omit incorrectly placed commas.

  1. I finally found my keys and I got to work just in time.
  2. Mrs. Contreras threw out her old coffee table, and cleaned the carpet.
  3. Taking the elevator to the roof we hoped we could see the skyline, and the bay.
  4. Though Susan wasn’t feel well she went to the store anyway and bought ice cream pizza, and candy.
  5. I let my neighbor borrow my phone, because she said hers was tapped by the police.


Use semicolons to connect two independent clauses when the second clause restates the first, or when the two clauses are closely related.

Example 1 - Road construction in Seattle has hindered travel around town; streets have become covered with bulldozers, trucks, and cones.

The second independent clause is describing the same situation as the first, but in a different manner.

Example 2 - It rained heavily during the afternoon; however, we still managed to have a picnic.

The second independent clause is linked to the first with a semicolon and a conjunctive adverb. Whenever you use a conjunctive adverb, either after a semicolon or at the beginning of the sentence, place a comma after it.

Here is a list of common conjunctive adverbs. Be wary of confusing conjunctive adverbs with subordinating conjunctions, for they have distinctly different uses. For a list of subordinating conjunctions, see Chapter 12, lesson 1.

Besides Hence However Incidentally Indeed Likewise
Meanwhile Moreover Nevertheless Similarly Still That is
Thereafter Therefore Thus Undoubtedly In fact As a result

Use a semicolon to separate elements in a sequence when those elements already have commas within them. Doing so clarifies for the reader how the commas are functioning.

Example 1 - Recent sites of the Summer Olympic Games include Beijing, China; Athens, Greece; Sydney Australia; and Atlanta, Georgia.

The semicolons separate the larger elements, while the commas separate the city and country within each element.

Review Questions

For each sentence, insert missing semicolons or omit incorrectly placed semicolons.

  1. They gave the fire marshal kickback to look the other way consequently, the building went up in flames the very next year.
  2. The earthquake on March \begin{align*}22^{nd}\end{align*} was nearly a 6.0 on the Richter scale, however there was no loss of life.
  3. Ingrid received a huge bonus last Christmas; because she singlehandedly sealed the Union Plastics deal.
  4. The old industrial centers of America—Detroit, Michigan, Cincinnati, Ohio, Pittsburg, Pennsylvania—are attempting to find new ways to thrive in a tech-heavy economy.
  5. I came in second place, my father hid his disappointment.


Use the colon after an independent clause when it is followed by a list, quotation, or other idea directly related to the independent clause.

Example 1 - Julie went to the store for some groceries: milk, bread, coffee, and cheese. The colon is announcing a list of items that describes the noun “groceries” in more detail.

Example 2 - The crier said those dreaded words: “The King is dead! Long live the king!” The colon is announcing a quote that specifies which “words” were said.

You can also use the colon to join two independent clauses when you wish to emphasize the second clause. The colon in this case announces that the second independent clause will complete the idea set up in the first.

Example 1 - Road construction in Yoknapatawpha County hindered travel along many routes: parts of Highway 56 and Vienda Drive are closed during construction.

The colon here announces that the first clause about “road construction” will be completed using the more specific detail from the second clause.

Review Questions

For each sentence, insert missing colons or omit incorrectly placed colons.

  1. An ammonia molecule consists of four atoms, one nitrogen and three hydrogen.
  2. George was turned away at the unemployment office they knew he still had a job.
  3. Some say there are traces of mercury in the town water supply: however, tests conducted by the EPA showed negative results.
  4. I know the perfect job for her; a politician.
  5. That street vendor sells everything you could possibly want; churros, hot dogs, and popsicles, for starters.


Use the hyphen to join two or more words serving as a single modifier before a noun. We use hyphens to clarify how multiple modifiers function before a noun.

Example 1 - You might not know it on first seeing her, but she is a well-known author.

Example 2 - That novelty shop on the boardwalk sells chocolate-covered peanuts.

Example 3 - Last night Ms. Munoz attended a high-school prom-night fundraiser.

If each word works separately to modify a noun, they are not hyphenated. We also do not use a hyphen when the compound modifiers come after a noun.

Example 1 - The old manor house was covered with creeping green Wisteria.

In this case, “creeping” is not modifying “green”; both words work as separate modifiers to describe “Wisteria.”

Example 2 - You might not know it on first seeing her, but the author is well known.

Example 3 - That novelty shop on the boardwalk sells peanuts that are chocolate covered.

Review Questions

For each sentence, insert missing hyphens or omit unnecessary hyphens.

  1. I have nothing to wear for my job interview but a paint splattered tie.
  2. Those ragged-old clothes I got from the attic were moth-ridden.
  3. Shelia’s cat brought home a mouse that was scared-stiff but otherwise unharmed.
  4. The recycling bin was filled with empty-plastic water bottles.
  5. Walter said I could use his, even though it was dog-eared and had missing pages.


We use apostrophes to indicate a possessive noun. Follow these rules to create possessive nouns with apostrophes.

1. Add [‘s] to the singular form of the word (even if it ends in –s).

Ex. the owner’s insurance, the waitress’s coat

2. Add [‘s] to the plural forms that do not end in –s.

Ex. the children’s game, the people’s opinion

3. Add [‘] to the end of plural nouns that end in –s.

Ex. the three friends’ cars, the workers’ benefits

4. Add [‘s] to the end of compound words.

Ex. my brother-in-law’s money

5. Add [‘s] to the last noun to show joint possession of an object.

Ex. Tom and Monica’s house

Apostrophes are also used in. We define a contraction as a word in which one or more letters have been omitted. The apostrophe shows this omission.


  • don’t = do not
  • I’m = I am
  • he’ll = he will
  • you’re = you are
  • won’t = will not
  • could’ve = could have

Review Questions

For each sentence, insert missing apostrophes or omit unnecessary apostrophes.

  1. Jack's and Jill's hill is nothing more than a mound of dirt on the southwest corner of Farmer Johns land.
  2. One's labor is proportional to ones' wealth.
  3. George shouldn't say that he'll be in the library when he obviously wont.
  4. Ill be back.
  5. Who'll referee those kid's soccer game if not for you're brother.

Dashes and Parentheses

Use dashes to set off or emphasize the content enclosed within them or the content that follows a dash. Dashes place more emphasis on the enclosed content than either parentheses or commas. We also use dashes to set off an appositive phrase that already includes commas.

An appositive is a word or phrase that adds explanatory or clarifying information to the noun that precedes it.

Example 1 - The U.S.S. Constitution became known as “Old Ironsides” during the War of 1812—during which the cannonballs fired from the British H.M.S. Guerriere merely bounced off the sides of the Constitution.

In this case, the phrase that comes after the dash is more important than the independent clause that comes before.

Example 2 - To some of you, my proposals may seem radical—even revolutionary. Here the dash works in conjunction with “even” to emphasize the adjective “revolutionary.”

Example 3- The cousins—Tina, Todd, and Sam—arrived at the party together. Here the dash is not being used for emphasis, but to stand in the place of additional commas that might confuse the reader.

Whereas dashes are used to emphasize content, parentheses are used to downplay content. They place less emphasis on the enclosed content than commas. Use parentheses to set off nonessential material—such as dates, clarifying information, clarifying information, or sources—from a sentence

Example 1 - Muhammad Ali (1942-present), arguably the greatest boxer of all time, claimed he would “float like a butterfly, sting like a bee.”

Example 2 - Denis Johnson’s new novel (which is bound in a luminous red hardback cover) is a worthy addition to the crime fiction genre.

Notice that information enclosed in parentheses has little relevance to the primary idea or meaning of the sentence.

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