5.3 Punctuation
Key Takeaways
- Commas separate list items, set off introductory and nonessential elements, and precede a coordinating conjunction joining independent clauses
- Semicolons join closely related independent clauses and separate list items that already contain commas
- Colons introduce a list, explanation, or quotation and must follow a complete independent clause
- Apostrophes show possession (the nurse's chart) and form contractions (don't, it's = it is)
- In American English, periods and commas always go inside closing quotation marks
Punctuation Signals Meaning
Punctuation marks are the road signs of writing—they tell the reader where to pause, stop, group, or connect ideas. On the TEAS, punctuation items rarely ask for a definition; instead they show you a sentence and ask which version is punctuated correctly. That means you must know the rule behind each mark, not just recognize it. The five marks tested most often are the comma, semicolon, colon, apostrophe, and quotation marks.
Commas: The Most Tested Mark
The comma has more rules than any other mark, and the test exploits the rules that writers most often break.
| Comma Rule | Example |
|---|---|
| Separate items in a series | She gathered gauze, tape, and scissors. |
| Before a coordinating conjunction joining two independent clauses | The IV was started, and fluids began. |
| After an introductory word, phrase, or clause | After the rounds, the team charted. |
| Around nonessential (extra) information | Dr. Lee, our supervisor, signed the order. |
| Between coordinate adjectives | a calm, capable nurse |
| With direct address and dates | Doctor, the patient is ready; July 4, 2026 |
The big trap is the comma splice—using a comma alone to join two independent clauses. "The patient improved, she was discharged" is wrong; it needs a conjunction, semicolon, or period. Equally, do not put a comma between a subject and its verb ("The senior nurse, reviewed the chart" is incorrect).
Semicolons and Colons
The semicolon has two jobs:
- Join two closely related independent clauses without a conjunction: "The surgery succeeded; the patient is recovering."
- Separate list items that contain internal commas: "Sites include Boston, MA; Denver, CO; and Reno, NV."
A semicolon must have a complete independent clause on both sides (except in the list-with-commas case). If only one side is independent, you need a different mark.
The colon introduces something—a list, an explanation, or a quotation—and the words before the colon must form a complete sentence.
- Correct: "She needs three items: gauze, tape, and scissors."
- Incorrect: "She needs: gauze, tape, and scissors." ("She needs" is not a complete thought before the colon.)
- Explanation use: "The cause was clear: dehydration."
Apostrophes
The apostrophe does two things—shows possession and forms contractions.
| Use | Rule | Example |
|---|---|---|
| Singular possession | add 's | the nurse's badge |
| Plural ending in -s | add only ' | the nurses' lounge |
| Plural not ending in -s | add 's | the children's ward |
| Contraction | apostrophe marks dropped letters | do not → don't |
The most-tested apostrophe errors are the possessive-vs-contraction pairs. Its is possessive ("the unit changed its policy"); it's means "it is." Whose is possessive; who's means "who is." Plural nouns do not take an apostrophe ("three nurses," not "three nurse's").
Quotation Marks and End Punctuation
Quotation marks enclose direct speech and the titles of short works (articles, poems, short stories). In American English, the placement of nearby punctuation follows fixed rules:
- Periods and commas go inside the closing quotation mark: She said, "The vitals are stable."
- Semicolons and colons go outside: She called it "routine"; the chart disagreed.
- Question marks and exclamation points go inside only if they belong to the quote: He asked, "Is the room ready?" but Did she really say "routine"?
End Punctuation at a Glance
| Mark | Use | Example |
|---|---|---|
| Period (.) | Ends a statement or mild command | Chart the intake. |
| Question mark (?) | Ends a direct question | Is the patient stable? |
| Exclamation point (!) | Ends an urgent or emotional statement | Call a code! |
Hyphens and Dashes (Quick Reference)
A hyphen joins compound adjectives before a noun (a well-known surgeon, a 10-year-old patient) and spelled-out compound numbers (twenty-one). An em dash (—) sets off an abrupt break or emphasis: "The result—surprisingly—was negative."
Worked Example: Choose the correctly punctuated sentence.
(A) The lab confirmed the result, the doctor adjusted the dose. (B) The lab confirmed the result; the doctor adjusted the dose. (C) The lab confirmed the result: the doctor adjusted the dose. (D) The lab confirmed the result the doctor adjusted the dose.
Step 1 – Count the clauses. "The lab confirmed the result" and "the doctor adjusted the dose" are both complete independent clauses.
Step 2 – Eliminate the errors. (A) is a comma splice; (D) is a fused run-on; (C) misuses the colon, which should introduce a list or explanation, not link two equal statements.
Step 3 – Confirm the legal join. A semicolon correctly links two closely related independent clauses, so (B) is right.
Answer: (B).
Which sentence uses a colon correctly?
Which sentence correctly uses the apostrophe?
In American English, where do a period and a comma go relative to closing quotation marks?
Insert the missing comma. Type the single word that should be immediately followed by a comma: "After the morning rounds the resident updated every chart."
Type your answer below