How to punctuate by rule, not by pause
TEAS 7 outline: Standard English punctuation
Also covers HESI A2 Grammar (Punctuation and capitalization)
- Punctuate by counting complete clauses, not by where you pause.
- Join two sentences with a period, semicolon, or comma plus FANBOYS.
- A colon must follow a complete sentence.
- Apostrophes show ownership or missing letters, never plain plurals.
- In US English, periods and commas go inside quotation marks.
Key facts
- When a coordinating conjunction (for, and, nor, but, or, yet, so) joins two parts of a sentence, put a comma before it only if both parts are independent clauses; no comma when the second part has no subject of its own.
- Put a comma after an introductory dependent clause or long introductory phrase, and between items in a series of three or more (the comma before the final and is a style choice).
- Set off nonessential information with a pair of commas; do not use commas around essential information, including clauses that begin with that.
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- A semicolon joins two independent clauses without a conjunction, goes before a transition such as however (with a comma after it), and separates list items that already contain commas.
- A colon must follow a complete sentence and introduces a list, explanation or quotation.
- Singular possessive adds 's (the patient's chart); plural ending in s adds only an apostrophe (the nurses' lounge); plural not ending in s adds 's (the children's ward).
- In US English, periods and commas go inside closing quotation marks; colons and semicolons go outside; question marks go inside only if the quoted words are the question.
Quick check1 question · 2 more at the end
Which of the following sentences correctly shows that the lounge is shared by all of the nurses on the unit?
Correct answer: C.
To make a plural noun that already ends in s possessive, add only an apostrophe after the s: nurses'. A singular owner adds 's (one nurse's lounge), and a plural that does not end in s, such as children, adds 's (children's). Check first whether the owner is one person or many.
A Nurse's shows a single owner, but the lounge belongs to many nurses.
B Without an apostrophe, nurses is a plain plural and does not show ownership.
C Correct: nurses is a plural ending in s, so it takes only an apostrophe after the s.
D A plural ending in s does not take an extra 's; nurses's adds a letter that is not needed.
Full lesson
Each part starts with its main idea. Open a part when you want the details.
The short answer: Punctuate by counting complete clauses, not by where you would pause. Join two complete sentences with a period, a semicolon, or a comma plus and, but, or, so, for, nor or yet. A colon must follow a complete sentence. Apostrophes show ownership or missing letters, not plurals. In US English, periods and commas go inside quotation marks.
1 How should you work a punctuation question?Punctuation follows sentence structure, so ignore where you would pause when reading aloud. 1 min
Punctuation follows sentence structure, so ignore where you would pause when reading aloud. Run this check on each choice:
- Find the clauses. Mark each subject–verb pair and ask whether it could stand alone as a sentence (an independent clause).
- Name the job of each mark: joining clauses, listing, setting off extra information, showing ownership, or quoting.
- Match the job to the rule in the tables below.
- Scan the rest of the sentence. Wrong options often fix one mark and break another.
2 When do you need a comma?Every comma needs a rule behind it, and "it felt like a pause" is not a rule. 1 min
Every comma needs a rule behind it, and "it felt like a pause" is not a rule.
| Rule | Correct | Incorrect | Quick test |
|---|---|---|---|
| Three or more items in a series | We need gloves, gowns, and masks. | We need gloves gowns and masks. | Count the items |
| After an introductory dependent clause | When the alarm rang, the nurses checked the monitors. | When the alarm rang the nurses checked the monitors. | Does it open with when, because, if, although? |
| Before for, and, nor, but, or, yet, so joining two independent clauses | The lab closed early, so the samples went downstairs. | The lab closed early so, the samples went downstairs. | Could both halves stand alone? |
| …but not between two verbs sharing one subject | The aide washed her hands and put on gloves. | The aide washed her hands, and put on gloves. | Does the second half have its own subject? |
| Around nonessential information | Dr. Okafor, who runs the sleep clinic, spoke first. | Dr. Okafor who runs the sleep clinic, spoke first. | Delete it; is the meaning the same? |
| No commas around essential information | Patients who miss two visits must reschedule. | Patients, who miss two visits, must reschedule. | Delete it; does the meaning change? |
A clause beginning with that is essential, so it never takes commas. The comma before and in a series (the serial or Oxford comma) is a style choice; AP style skips it.
3 When do semicolons and colons fit?A semicolon joins equal, complete sentences, while a colon announces what comes next. 1 min
A semicolon joins equal, complete sentences, while a colon announces what comes next.
| Mark and rule | Correct | Incorrect |
|---|---|---|
| Semicolon: two independent clauses, no conjunction | The pharmacy is closed; the clinic is open. | The pharmacy is closed, the clinic is open. |
| Semicolon before however, therefore, etc., comma after | The test was long; however, most students finished. | The test was long, however most students finished. |
| Semicolon: list items that contain commas | We met in Dayton, Ohio; Erie, Pennsylvania; and Troy, New York. | We met in Dayton, Ohio, Erie, Pennsylvania, and Troy, New York. |
| Colon: after a complete sentence, before a list or explanation | Bring two things: your badge and a pen. | Bring: your badge and a pen. |
Colon test: cover everything after it. If what is left is not a full sentence, the colon is wrong.
4 How do apostrophes work?Apostrophes do two main jobs, showing ownership and replacing missing letters. 1 min
Apostrophes do two main jobs, showing ownership and replacing missing letters.
| Use | Correct | Incorrect |
|---|---|---|
| One owner: add 's | the patient's chart | the patients chart |
| Plural owner ending in s: add ' | the nurses' lounge | the nurses's lounge |
| Plural owner not ending in s: add 's | the children's ward | the childrens' ward |
| Contraction | it's (it is), don't (do not) | its raining |
| Never for a plain plural | two doctors | two doctor's |
| Never for possessive pronouns | its, yours, theirs, whose | it's (as possessive), their's |
Quick test: turn it into an "of" phrase. The chart of the patient proves you need patient's.
5 Where do quotation marks and nearby punctuation go?In US English, periods and commas go inside the closing quotation mark. 1 min
In US English, periods and commas go inside the closing quotation mark.
- Inside: "Take a seat," the clerk said.
- Outside: colons and semicolons. She called it "routine"; the doctor agreed.
- Question mark: inside if the quoted words ask the question (He asked, "Is it fasting?"), outside if the whole sentence asks (Did she say "fasting"?).
- Exact words only: She said that she was tired reports speech without quoting it, so it takes no quotation marks.
Common mistakes
The traps students fall into most. Read these before you practice.
Watch out: A comma alone cannot join two complete sentences; that is a comma splice, even when the second one starts with however.
Watch out: Do not put a comma between two verbs that share one subject: the aide washed her hands and put on gloves, not hands, and put on gloves.
Watch out: A colon after a verb or after such as or including is wrong because the words before it are not a complete sentence.
Watch out: Plain plurals never take an apostrophe, and neither do possessive pronouns: two doctors, its, theirs, whose.
Watch out: A nonessential element needs commas on both sides; a choice with only the opening comma is wrong.
How to remember it
Two full sentences can be joined only by a strong joint. The everyday strong joints are a period, a semicolon, or a comma plus FANBOYS (for, and, nor, but, or, yet, so). A colon also works when the second sentence explains the first.
Self-check:
- Fix this: "The scale was broken, the nurse used another one."
- Does "Students who study daily" need commas? Use the delete test.
- Write the possessive for the coats belonging to three women.
Show answers
- "The scale was broken; the nurse used another one."
- Both halves are independent clauses, so a comma alone is too weak.
- A period works too, and so does a comma plus so: "The scale was broken, so the nurse used another one."
- No commas.
- Delete "who study daily," and the meaning changes: it no longer says which students.
- That makes it essential information, and essential information takes no commas.
- The women's coats.
- Women is a plural that does not end in s, so add 's.
- "Of" test: the coats of the women.