22 Comma Rules

When should you use a comma and when should not? It could be a life or death matter. After all, “Let’s eat Grandma” is considerably different than “Let’s eat, Grandma.” Sometimes these mechanics and grammar rules do serve a purpose.

English language-arts teachers, like copy editors, live by the style guides. Safe to safe, the comma rules are certainly in flux. I subscribe to the “When in doubt, leave it out” generalization when it comes to comma usage. However, it’s always important to know the rule, before you intentionally violate the rule.

Before we jump in, would you like to add a free (for now) extension that automatically inserts all 22 comma rules into your students’ Google docs and slides?

Writer Response

Writing Feedback

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2 Speaker Tag In dialogue sentences, place commas before and after a middle speaker tag to the left of both  quotation marks. Question marks and exclamation points can also separate speaker tags from dialogue. Example: “But if you don’t,” he shouted “you will never win.”

3 Speaker Tag In dialogue sentences, place commas before an ending speaker tag to the left of the quotation marks. Question marks and exclamation points can also separate speaker tags from dialogue. Example: “Okay. I will give you another chance,” he responded.

4 Appositive Use commas to set apart appositives. An appositive is a noun or pronoun placed next to another noun or pronoun to identify, define, or describe it. The     appositive can be a word, phrase, or clause. Example: That man, the one with the hat, left town quickly.

5 Commas in Series Use commas after each item in lists (except the last). Use commas after each item in lists, except the last one. Example: John, Jane, and Jose left early.

6 Introductory Word Use commas only after introductory words which receive special emphasis. Examples: Conversely, you could listen. Then I went home.

7 Introductory Phrase Use commas after introductory phrases when followed by a modifying noun or pronoun. Example: Bold and beautiful, the statue was popular. Don’t use commas if the phrase modifies the following noun or pronoun or if another part of speech follows the phrase. Examples: A bold and beautiful statue was popular. Bold and beautiful was the popular statue.

* Exception: Avoid using commas after short (four words or less) introductory prepositional phrases. Examples: Under the tree he hid. Under the shady oak tree, he hid.

8 Introductory Dependent Clauses A dependent clause includes a noun or pronoun and connected verb, but does not express a complete thought. Place a comma following introductory dependent clauses. Examples: Even though I listened, I didn’t understand.

9 Ending Dependent Clause A dependent clause includes a noun or pronoun and connected verb, but does not express a complete thought. Don’t  place a comma before an ending dependent clause. Example: I never got her letter although she did write.

10 Geography Place commas between related geographical place names and after the last place name,  unless it appears the end of a sentence. When the place name is a possessive, this rule does not apply. Examples: She lived in Rome, Italy, for a year. Rome, Italy’s traffic is congested.

11 Dates Use commas to separate number dates and years. Don’t place a comma following the year. Example: It all happened on May 3, 1999. On May 4, 1999 we went back home.

12 Beginning Direct Address Use commas to separate nouns of direct address. The noun can be a word, phrase, or clause. If at the beginning of the sentence, one comma follows. Examples: Kristen, leave some for your sister. Officer Daniels, I need your help. Whoever you are, stop talking.

13 Middle Direct Address Use commas to separate nouns of direct address. The noun can be a word, phrase, or clause. If in the middle of the sentence, one comma goes before and one follows. Examples: If you insist, Dad, I will. If you insist, Your Honor, I will.

14 Ending Direct Address Use commas to separate nouns of direct address. The noun can be a word, phrase, or clause. If at the end of the sentence, one comma goes before the noun. Examples: Just leave a little bit, honey. Just leave a little bit, best girlfriend.

15 Compound Sentence Use commas before coordinating conjunctions to join two independent clauses if one or more of the sentences is long. Example: I liked her, and she definitely said that she liked me.

16 Commas to Enclose Parenthetical Expressions Use commas before and after words that interrupt the flow of the sentence. If the interruption is minimal, you may leave out the commas. Example: The best way to see the game, if you can afford it, is in person.

17 Commas to Set Off Non-restrictive Clauses A nonrestrictive clause can be removed from a sentence without changing the meaning of the sentence. The relative pronouns who, whom, whose, and which, but not that, begin nonrestrictive relative clauses. Use commas to set off nonrestrictive relative clauses from the noun or pronoun before the clause. Example: The girl, who sits in the corner, is sleepy.

18 Commas and Restrictive Clauses A restrictive clause can’t be removed from a sentence without changing the meaning of the sentence. A restrictive clause limits

22 Comma Rules with Examples

22 Comma Rules

the meaning of the independent clause to which it is attached. Don’t use commas before and after restrictive clauses. Example: The student who wins the most votes will be elected Student Council President.

19 Comma and Abbreviations These abbreviations: Sr. (senior), Jr. (junior), and etc. (et cetera) are always preceded by a comma. Don’t place commas after these abbreviations. Examples: Howard, Sr. had Howard, Jr., take out the trash, water the lawn, pull weeds, etc.

20 Comma and Duplicate Words Place commas between repeated words when needed to improve clarity. Examples: Tommy and Pam moved in, in May.

21 Comma to Replace Missing Words Use commas to replace omitted words, especially the word that. Examples: I am a vegetarian; my wife, a meat-eater. Win some, lose some. What I mean is, she hasn’t changed her diet and followed mine.

22 Comma in Parenthetical Citations Place a comma after each author’s name, except the last in a multiple author citation. Don’t use a comma between the author(s) and the page number(s). Example: (Peabody, Jones, and Smith 14) Don’t place a comma between different authors or resource titles citing information; use a semicolon. Examples: (Peabody 16; Jimenez 55) (The Nature of Change; Wrong Policy)

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Syntax Programs

Pennington Publishing Grammar Programs

Teaching Grammar, Usage, and Mechanics (Grades 4, 5, 6, 7, 8, and High School) are full-year, traditional, grade-level grammar, usage, and mechanics programs with plenty of remedial practice to help students catch up while they keep up with grade-level standards. Twice-per-week, 30-minute, no prep lessons in print or interactive Google slides with a fun secret agent theme. Simple sentence diagrams, mentor texts, video lessons, sentence dictations. Plenty of practice in the writing context. Includes biweekly tests and a final exam.

Grammar, Usage, and Mechanics Interactive Notebook (Grades 4‒8) is a full-year, no prep interactive notebook without all the mess. Twice-per-week, 30-minute, no prep grammar, usage, and mechanics lessons, formatted in Cornell Notes with cartoon response, writing application, 3D graphic organizers (easy cut and paste foldables), and great resource links. No need to create a teacher INB for student make-up work—it’s done for you! Plus, get remedial worksheets, biweekly tests, and a final exam.

Syntax in Reading and Writing is a function-based, sentence level syntax program, designed to build reading comprehension and increase writing sophistication. The 18 parts of speech, phrases, and clauses lessons are each leveled from basic (elementary) to advanced (middle and high school) and feature 5 lesson components (10–15 minutes each): 1. Learn It!  2. Identify It!  3. Explain It! (analysis of challenging sentences) 4. Revise It! (kernel sentences, sentence expansion, syntactic manipulation) 5. Create It! (Short writing application with the syntactic focus in different genre).

Get the Diagnostic Grammar, Usage, and Mechanics Assessments, Matrix, and Final Exam FREE Resource:

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  1. Chip Clark
    March 19th, 2021 at 08:16 | #1

    Mr. Pennington,

    By numerical count, I only see 21 rules here. What did you intend on the first rule being?

  2. March 29th, 2021 at 10:47 | #2

    Oops! 21 it is.

  3. December 18th, 2021 at 16:30 | #3

    “I, like many teachers subscribe to the ‘When in doubt, leave it out’ generalization when it comes to comma usage.”

    And right off the bat we go off the rails. 🙂

    “I, like many teachers[COMMA] subscribe to the ‘When in doubt, leave it out’ generalization when it comes to comma usage.”

  4. December 23rd, 2021 at 07:38 | #4

    Got me! Fixed.

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