5.3 Conventions of Punctuation
Key Takeaways
- Commas are used to separate items in a series, set off introductory elements, isolate nonessential clauses, and join independent clauses alongside a coordinating conjunction.
- Semicolons join closely related independent clauses without a coordinating conjunction and separate complex list items that already contain internal commas.
- Colons must follow a grammatically complete independent clause to introduce lists, formal explanations, or direct quotations.
- Apostrophes are restricted to indicating possession for nouns and forming contractions, and they should never be used on possessive pronouns.
Conventions of Punctuation
Punctuation guides readers through written text. On the TSIA2 ELAR, you must know the precise rules for commas, semicolons, colons, and apostrophes to identify errors and choose the best revisions.
The Comma (,)
Commas are the most versatile punctuation marks, but they are also the most frequently misused. There are four primary rules for comma usage:
1. Separating Items in a Series
Use commas to separate three or more words, phrases, or clauses in a list. The final comma before the coordinating conjunction is the Oxford comma. Standardized exams expect the Oxford comma to prevent ambiguity.
- Example: The research paper analyzed the economic, political**, and** social factors of the war.
2. Setting Off Introductory Elements
An introductory phrase or clause sits at the beginning of a sentence. It provides context but cannot stand alone. A comma should separate it from the main independent clause.
- Example: To prepare for the exam, she designed a comprehensive study schedule.
- Example: Unfortunately, the experiment did not produce the expected results.
3. Nonessential Modifiers (Appositives and Relative Clauses)
A nonessential modifier adds extra information that is not critical to the core meaning of the sentence. If you remove the phrase, the sentence still makes sense. These modifiers must be set off with commas.
- Example: Dr. Chen, who joined the faculty last fall, has received a prestigious grant.
In contrast, an essential modifier is critical to identifying the noun it describes. Do not set off essential modifiers with commas.
- Example: The professor who joined the faculty last fall has received a prestigious grant.
4. Joining Independent Clauses
When two independent clauses are joined by a coordinating conjunction (FANBOYS), a comma must precede the conjunction.
- Example: The library was quiet, but she struggled to concentrate.
The Semicolon (;)
Semicolons are stronger than commas but weaker than periods. They serve two main purposes:
1. Linking Closely Related Independent Clauses
A semicolon can connect two independent clauses without a coordinating conjunction.
- Example: The first survey focused on suburban communities; the second targeted urban areas.
2. Separating Items in a Complex List
When list items already contain commas, use semicolons to separate the main items.
- Example: The conference attendees included Dr. Smith, a biologist; Ms. Jones, a chemist; and Mr. Davis, a physicist.
The Colon (:)
Colons signal to the reader that information is about to be explained or listed. The most critical rule for colons is that the clause preceding the colon must be an independent clause.
1. Introducing Lists
Use a colon to introduce a list after a complete sentence.
- Incorrect: The requirements for the course include: a research paper, a presentation, and a final exam.
- Correct: The course requires three final deliverables: a research paper, a presentation, and a final exam.
2. Introducing Explanations or Elaborations
Use a colon to connect two independent clauses if the second clause explains, illustrates, or expands on the first.
- Example: The company has a strict policy: no personal calls are allowed during work hours.
3. Introducing Quotations
Use a colon to introduce a formal or long block quotation.
- Example: The dean's letter made the university's stance clear: "We are committed to academic excellence."
The Apostrophe (')
Apostrophes indicate possession or form contractions. They are never used to make standard nouns plural.
1. Possessives
- Singular Nouns: Add 's. (e.g., the student's notebook)
- Plural Nouns Ending in -s: Add only an apostrophe at the end. (e.g., the students' notebooks)
- Irregular Plural Nouns: Add 's. (e.g., the children's play area)
2. Contractions vs. Possessive Pronouns
A common exam trap involves confusing contractions with possessive pronouns. Possessive pronouns never use apostrophes.
| Possessive Pronoun (No Apostrophe) | Contraction (Uses Apostrophe) |
|---|---|
| its (belonging to it) | it's (it is / it has) |
| their (belonging to them) | they're (they are) |
| whose (belonging to whom) | who's (who is) |
| your (belonging to you) | you're (you are) |
- Incorrect: The dog wagged it's tail. (Should be "its").
Punctuation Quick-Reference Table
| Punctuation Mark | Primary Function | Exam Tip | Example |
|---|---|---|---|
| Comma (,) | Separates list items, introductory elements, and nonessential phrases. | Never place a comma between a subject and its verb. | Although tired, she finished. |
| Semicolon (;) | Joins two independent clauses; acts as a separator in complex lists. | Ensure both clauses can stand alone. | He wrote the code; she tested it. |
| Colon (:) | Introduces lists, explanations, or quotes. | The clause before the colon must be independent. | She had one goal: success. |
| Apostrophe (') | Shows possession or forms contractions. | Possessive pronouns like its and whose never have apostrophes. | It's a shame the cat lost its toy. |
Applying these targeted rules will help you navigate punctuation questions quickly and accurately on the TSIA2.
Choose the sentence that is punctuated correctly.
Read the sentence: 'The research project will require travel to three main sites: Austin, Texas, Chicago, Illinois, and Seattle, Washington.' Identify the correct way to punctuate the list items.
Which of the following sentences correctly distinguishes between possessives and contractions?
Read the following sentence: 'The director has one main rule for the office, employees must submit their reports by five o'clock.' Which revision correctly punctuates the connection between the clauses?