Free ATI TEAS 7 English & Language Usage guide

October 2026 - Punctuation Study Guide

Commas separate items and set off introductory or non-essential elements. Semicolons join related independent clauses, colons introduce lists or explanations, and dashes mark an abrupt break. A comma after an introductory phrase is nearly always correct; a comma between a subject and its verb nearly never is.

English & Language Usage guide Conventions of standard English · 12 scored questions 6 min read

The four comma rules that cover almost everything

  • In a series — soap, water, and a clean towel. The comma before "and" is optional in general usage but standard in academic writing.
  • After an introductory element — After the handover, the ward settled.
  • Around non-essential information — The senior nurse, who had worked there for twenty years, disagreed. Remove the middle and the sentence still works.
  • Before a coordinating conjunction joining two independent clauses — The ward was full, but every patient was seen.

Never put a single comma between a subject and its verb. The nurse on the evening shift, checked every chart is wrong however long the subject is. A pair of commas around an interruption is fine; one comma alone splitting the sentence is not.

Semicolon, colon, dash

MarkUseExample
Semicolon Joins two closely related independent clauses The ward was short-staffed; handover ran late.
Semicolon Separates list items that already contain commas Leeds, Yorkshire; Bath, Somerset; Ely, Cambridgeshire
Colon Introduces a list, an explanation or a quotation She brought three things: gloves, a chart and a pen.
Dash Marks an abrupt break or emphasis He checked the dose — twice — before drawing it up.
Parentheses Enclose an aside of lower importance The dose (2 mg) was confirmed.

The colon rule people miss

What comes before a colon must be a complete sentence. She brought: gloves, a chart and a pen is wrong, because "she brought" cannot stand alone. She brought three things: gloves, a chart and a pen is right.

The same test settles the semicolon. Both sides of a semicolon must be complete sentences — if either half could not stand alone, a semicolon is the wrong mark.

Essential and non-essential

This decides whether commas are needed at all, and it changes the meaning.

  • The nurse who wrote the note has left. — no commas. The clause identifies which nurse, so it is essential.
  • The nurse, who wrote the note, has left. — commas. There is only one nurse in question; the clause is extra information.
  • Test by removing the clause. If the sentence loses essential meaning, leave the commas out.

Choosing between marks

Worked example

Punctuate: The audit found one recurring problem staff were not documenting the time of administration

  1. Identify the two parts: a complete statement, then what the problem was.
  2. The second part explains the first, which points to a colon.
  3. Check the colon rule: "The audit found one recurring problem" is a complete sentence, so a colon is permitted.
  4. A semicolon would also be grammatical here, but a colon signals explanation, which is the actual relationship.

The audit found one recurring problem: staff were not documenting the time of administration. The colon announces that what follows explains what came before.

Terms to know

Comma
Separates items and sets off introductory or non-essential elements.
Semicolon
Joins two independent clauses, or separates complex list items.
Colon
Introduces a list, explanation or quotation after a complete sentence.
Dash
Marks an abrupt break or adds emphasis.
Parentheses
Enclose an aside of lesser importance.
Essential clause
A clause that identifies which one is meant. No commas.
Non-essential clause
Extra information that could be removed. Takes commas.
Serial comma
The comma before the final "and" in a list.

What the TEAS asks most

The same core ideas appear in different wording. If you can answer these without stopping to think, you have what this section requires.

Which sentence is punctuated correctly?

Check for a comma splice first, then a comma between subject and verb, then the colon rule.

Where should a comma be inserted?

After an introductory element, around a non-essential clause, or before a conjunction joining two clauses.

Which mark correctly joins these two clauses?

A semicolon if both halves stand alone; a colon if the second explains the first.

Key points

  • Commas: series, after an introduction, around non-essential information, before a joining conjunction.
  • Never a single comma between a subject and its verb.
  • Both sides of a semicolon must be complete sentences.
  • What comes before a colon must be a complete sentence.
  • Essential clauses take no commas; non-essential ones do.

Review quiz

4 questions on this topic, each with the reasoning worked through. Pick an answer to see how it went, or open the explanation straight away.

  1. Question 1 of 4

    Which sentence is punctuated correctly?

    Answer choices for question 1

    Show the answer and explanation

    Correct answer: B. The ward was short-staffed; handover ran late.

    Both halves are complete sentences and closely related, which is exactly what a semicolon is for. The first is a comma splice, the third pairs a semicolon with a conjunction that is not needed, and the fourth separates a subject from its verb.

  2. Question 2 of 4

    Which sentence uses a colon correctly?

    Answer choices for question 2

    Show the answer and explanation

    Correct answer: B. The trolley contained three items: gloves, gauze and tape.

    What precedes a colon has to stand alone as a sentence, and "The trolley contained three items" does. "The trolley contained" does not, which rules out the first, and the remaining two place the colon inside the sentence rather than at the point of introduction.

  3. Question 3 of 4

    Which sentence needs commas around the underlined clause: The nurse who wrote the incident report has been asked to attend.?

    Answer choices for question 3

    Show the answer and explanation

    Correct answer: B. It should stay as it is, because the clause identifies which nurse is meant.

    The clause tells you which nurse of several, which makes it essential — and essential clauses take no commas. Adding them would imply that only one nurse exists and the detail is incidental, which changes the meaning.

  4. Question 4 of 4

    Where should a comma be added? After reviewing the notes the consultant changed the plan.

    Answer choices for question 4

    Show the answer and explanation

    Correct answer: B. After "notes"

    The introductory element ends at "notes", so the comma goes there to mark where the main clause begins. Placing it after "consultant" would split the subject from its verb, which is the one position a comma may never occupy.

Put this TEAS topic into practice

Build a set on punctuation and use the rationale on every question to reinforce what you just reviewed.