Commas and Comma Splices

• Commas are punctuation marks signaling a brief pause.
• They separate list elements, set off introductory phrases, and join independent clauses.
• Correct comma use boosts writing clarity and readability.

Comma Splices

• A comma splice joins two independent clauses with only a comma.
• An independent clause contains a subject and verb and can stand alone.
• "I went to the store, I bought some milk" is an example of a comma splice.
• Correct comma splices by:
  • Replacing the comma with a period, creating two sentences.
  • Adding a coordinating conjunction (and, but, or, nor, for, so, yet) after the comma.
  • Using a semicolon.
  • Subordinating one clause with a subordinating conjunction (because, although, if, since).

Commas in Lists

• Commas separate three or more words, phrases, or clauses in a list.
• Example: "I need to buy milk, bread, and eggs."
• The final comma before "and" or "or" is the Oxford (or serial) comma.
• Style guides vary on Oxford comma use; AP omits it, Chicago recommends it.
• Be consistent with Oxford comma use within a document.
• Use semicolons instead of commas for clarity with long or complex list items.

Commas with Coordinating Conjunctions

• Use a comma before a coordinating conjunction (and, but, or, nor, for, so, yet) joining two independent clauses.
• Example: "She wanted to go to the party, but she had too much work to do."
• The comma may be omitted with short, closely related clauses.
• Example: "He ran and she walked."
• Don't use a comma before a coordinating conjunction joining list items, unless the items contain commas.

Commas with Introductory Elements

• Use a comma after an introductory word, phrase, or clause preceding the main clause.
• Example (Introductory word): "Well, I suppose we could try again."
• Example (Introductory phrase): "After the long journey, we were glad to be home."
• Example (Introductory clause): "Because it was raining, we decided to stay inside."
• Short introductory phrases (under five words) may not need a comma if clarity isn't compromised.

Commas with Parenthetical Elements

• Use commas to set off parenthetical elements within a sentence.
• Parenthetical elements add extra, non-essential information.
• Parenthetical element examples:
  • Nonrestrictive appositives (renaming nouns): "My brother, who is a doctor, lives in New York."
  • Nonrestrictive relative clauses (extra noun info): "The book, which I borrowed from the library, is overdue."
  • Interjections: "This is, after all, a very important decision."
  • Conjunctive adverbs (however, therefore, etc.): "She was tired; however, she kept working."
• Restrictive elements (essential to the sentence's meaning) do not need commas.
• Example (Restrictive relative clause): "The book that I borrowed from the library is overdue" (identifies which book).

Commas with Direct Address, Interjections, and Tag Questions

• Use commas to set off names/titles in direct address.
• Example: "John, please close the door."
• Use commas to set off mild interjections.
• Example: "Oh, I didn't realize that."
• Use commas to set off tag questions.
• Example: "It's a beautiful day, isn't it?"

Commas with Dates, Addresses, and Titles

• Separate the day of the month from the year with a comma.
• Example: "July 4, 1776, was a significant day in American history."
• The comma is optional if only the month and year are given.
• Separate the street address from the city and the city from the state with a comma.
• Example: "He lives at 1600 Pennsylvania Avenue, Washington, D.C."
• Do not put a comma between the state and the zip code.
• Use commas to set off titles or degrees following a name.
• Example: "Jane Doe, M.D., is a renowned physician."

Misplaced Commas

• Avoid commas that disrupt sentence flow.
• Incorrect: "I like, to eat pizza."
• Incorrect: "She is a, very talented singer."
• Incorrect: "The car, that I bought, is red."

Commas for Clarity

• Use commas to prevent misreading, even if not strictly required.
• Example: "For most, the class was easy."
• When in doubt, adding or removing a comma should improve clarity.
• Clarity is key.

Conjunctive Adverbs

• Conjunctive adverbs (e.g., however, therefore) connect independent clauses.
• They usually follow a semicolon and are followed by a comma when connecting independent clauses.
• Example: "The weather was bad; therefore, we stayed inside."
• Set off conjunctive adverbs interrupting single clauses with commas.
• Example: "The play, however, was very enjoyable."

Coordinate Adjectives

• Coordinate adjectives modify the same noun equally.
• Separate coordinate adjectives with a comma.
• Example: "It was a cold, dark night."
• Test: insert "and" or reverse order. If the sentence still makes sense, they are coordinate.
• Do not separate non-coordinate adjectives with a comma.
• Example: "He drives a fast sports car."

Quotations

• Use a comma to introduce or separate a direct quotation.
• Example: "She said, 'I am going to the store.'"
• Omit the comma if the quotation integrates into the sentence.
• Example: "She said that she was going to the store."
• Commas and periods go inside closing quotation marks.
• Colons and semicolons go outside closing quotation marks.
• Question marks and exclamation points go inside if part of the quote; otherwise, outside.