MECHANICS

C: commas.

If your teacher marks “C” on your paper, do not merely add a comma; identify which of the comma rules below is applicable.

CA: use a comma between independent clauses.

The comma comes before coordinating conjunctions: “and,” “but,” “or,” “nor,” “yet” and “for.”

The comma is unnecessary if the clauses are short with no danger of misreading.

COMMA NEEDED: His first wife tried to poison herself, and his second tried to poison him.

COMMA UNNECESSARY: Fish are jumping and the cotton is high.

If a comma is required, it belongs before, not after, a conjunction:

WRONG: She tried her hardest but, the bar was too high.

RIGHT: She tried her hardest, but the bar was too high.

Do not confuse clauses with other word groups joined by “and” or “but”:

WRONG: She tried her hardest, but fell short of her goal.

RIGHT: She tried her hardest but fell short of her goal. (phrases, not clauses)

RIGHT: She tried her hardest, but she fell short of her goal. (clauses, not phrases)

The rule can apply to “or,” “for,” “yet” and “nor.” Remember that the key criterion is whether the things the conjunction joins are independent clauses (groups of words that can stand on their own as a sentence).

CLAUSES: He vowed, “I will win your heart, or I will die trying.”

PHRASES: He vowed, “I will win your heart or die trying.”

CLAUSES: “I would give up all I own, for you mean the world to me.”

PHRASES: “I would give up all I own for your love.”

CLAUSES: He did not win her heart, yet he survived.

PHRASES: His words were charming yet untrue.

CLAUSES: He did not win her heart, nor did he die trying.

PHRASES: He neither won her heart nor died trying.

For more information on commas with “and,” see CXA.

CI: use a comma after an introductory word group.

A comma sets off a subordinate phrase or clause from the main clause. Use no comma if the phrase is short and there is no danger of misreading:

Comma needed: By the time the plane arrived, most of the babies had stopped crying.

Comma unnecessary: By now her meeting must have ended. In a democracy all votes are equal.

Often even short introductory phrases are momentarily ambiguous without commas:

WRONG: After eating Goldilocks takes a nap in the bear’s bed.

RIGHT: After eating, Goldilocks takes a nap in the bear’s bed.

Illustration by Katharine Pyle (1863-1938)

The rule applies even if the introductory word group does not come at the beginning of the sentence. In the example below, the “if” clause modifies “I cannot play video games”:

WRONG: My parents never scold me, but if I do not finish my chores I cannot play video games.

RIGHT: My parents never scold me, but if I do not finish my chores, I cannot play video games.

The CI rule applies to an absolute phrase at the start of a sentence:

The universe safe once more, Superman returned to his normal identity.

C.Ser: use commas with a series of three or more words or phrases.

The series can consist of any part of speech. A comma is optional before the “and” or “or,” unless it is needed for clarity.

She eats the porridge, breaks the chair, and sleeps in the bed.

Goldilocks dashes out of bed, through the door and into the forest.

Aristotle classifies poetry as lyric, dramatic and narrative.

C.Ad: use commas between coordinate adjectives.

WRONG: loud meaningless chatter

RIGHT: loud, meaningless chatter

C.Wh: use a comma before a nonrestrictive element.

The rule usually applies to relative clauses beginning with “which,” “who,” “whom” or “whose.” It can apply to subordinate clauses beginning with “when,” “where” or “while.”

This rule is easier than it probably sounds. It merely tells you when to place a comma before pronouns beginning with “wh.”

NONRESTRICTIVE: Lions, which eat meat, are felines. (referring to all lions)

RESTRICTIVE: Lions which have manes are male. (only certain lions)

“Nonrestrictive” just means you are not talking about all lions. If a sentence would still make sense without the clause, it needs commas. “Lions are felines” is true, but “Lions are male” is not. A nonrestrictive clause in the middle of a sentence requires two commas: one before the clause and one after it.

WRONG: Her dad, who is sixty retired early.

RIGHT: Her dad, who is sixty, retired early.

Conversely, any comma before or after a restrictive element is wrong:

WRONG: The one on the far left, is my sister.

RIGHT: The one on the far left is my sister.

All clauses introduced with “that” are restrictive:

WRONG: My brother attended the same school, that I attend now.

RIGHT: My brother attended the same school that I attend now.

The rule applies to subordinate clauses beginning with “when,” “where” or “while” if they are restrictive:

RESTRICTIVE: She moved to the country, where she could escape city traffic.

NONRESTRICTIVE: She returned to the country where she was born.

C.App: use commas to set off appositives.

Do not confuse C.App with Cap.

An appositive is a noun phrase equivalent to another noun phrase in the sentence. If it comes in mid-sentence, it requires commas both before and after it:

WRONG: Bob, my postman lives on my street.

RIGHT: Bob, my postman, lives on my street.

Appositives require commas only if they are nonrestrictive (as explained in C.Wh, not essential to the meaning):

COMMAS: Our class president, Ron, gave a speech. (Ron is your only class president)

NO COMMAS: My classmate Ann plays the flute. (Ann is not your only classmate)

COMMAS: Galileo, the great astronomer, discovered the moons. (not essential to the meaning)

NO COMMAS: The Galilean moons are named for the astronomer Galileo. (essential)

For more information on appositives, see DM.Ap.

C.Tr: use commas to set off transitional phrases, wherever they are located.

However, cows moo.

Cows, of course, moo.

Cows moo, in fact.

Pigs, on the other hand, oink.

C.Inter: use commas before and after interrupting phrases and clauses.

I wake up early, even on weekends, for a walk.

Her name, I think, is Ellen.

Do not confuse restrictive modifying phrases and clauses with interrupting phrases. The sentences below have no commas because the interrupting elements are restrictive:

I go walking in the park for exercise.

The girl I think is Ellen is on the left.

CE: use a comma before a nonrestrictive element at the end of a sentence.

The comma indicates that the concluding phrase or clause is not part of the main structure of the sentence.

COMMA: He ran out the door, pausing to kiss his mother. (nonrestrictive phrase)

NO COMMA: He ran out the door in the back. (restrictive phrase)

COMMA: I like to jog early, when it is still cool. (nonrestrictive clause)

NO COMMA: I like to jog early in the morning. (restrictive clause)

Careless comma placement can change the meaning of a sentence:

The boy sent a letter to the girl hoping for news. (the girl hopes for news)

The boy sent a letter to the girl, hoping for news. (the boy hopes for news)

C.Cont: use commas to set off contrasts.

She wore blue, not white, at the wedding.

At the wedding she wore blue, not white.

CDA: use commas with direct address.

If the name comes in mid-sentence, use two commas: one before and one after it:

BEGINNING OF SENTENCE: Physician, heal thyself.

MIDDLE OF SENTENCE: Please, Superman, save our planet!

END OF SENTENCE: I’ll do my best, ma’am. Take that, villain!

Writers of dialogue sometimes forget to include the comma:

WRONG: “Mom are you there?” I asked.

RIGHT: “Mom, are you there?” I asked.

CYN: use commas with “yes” and “no”; use exclamation points or commas with interjections.

Yes, it is. No, sir. Hey, you! Well, have it your way.

An error common in dialogue is omission of the comma:

WRONG: “Yes I am,” she replied.

RIGHT: “Yes, I am,” she replied.

If direct address interrupts, you may need two commas:

TWO COMMAS: No, Einstein, you’ve been a bad dog.

CQ: use a comma to set off a tag question or a similar phrases.

TAG QUESTIONS: Today is Friday, isn’t it? You meant Friday, didn’t you?

SIMILAR PHRASES: It’s only Tuesday, I fear. Two aspirins, please.

CD: use a comma to set off dialogue.

Phrases introducing quotations or dialogue require commas if they use verbs like “says,” “asks,” “begs,” “insists” and “commands.”

He explained triumphantly, “To get to the other side!”

If the quotation comes first, a comma is still necessary unless a question mark or exclamation point closes the quotation:

“To get to the other side,” he explained triumphantly.

“Why did the chicken cross the road?” she asked.

CDN: use commas for writing conventions such as dates, numbers and titles.

5,280 feet

Portland, ME

John Smith, RN

five feet, two inches

Dates are conventionally written in two ways:

COMMA: June 16, 1904

NO COMMA: 16 June 1904

Add another comma after a date, address or title if the sentence continues:

Martin Luther King, Jr., was born on January 15, 1929, in Atlanta, Georgia.

C2nd: additional comma needed.

If your teacher marks “C2nd,” you have used one comma that requires you to add another comma elsewhere in the sentence. Determine where the second comma belongs and add it. If you are not sure where it belongs, or you want to know why it is necessary, review the section on Commas, especially C.Wh, C.App, C.Tr, C.Inter, C.Cont and CDA.

CX: unnecessary commas.

If your teacher marks “CX,” do not just write “CX.” Identify which rule is applies to your sentence.

CXA: use no comma between compound elements.

Use no comma before the coordinating conjunctions “and,” “or,” “nor,” “but” or “yet” when they join words and phrases:

If the conjunction joins clauses (word groups with subject and verb), a comma is needed unless the clauses are short and there is no danger of confusion:

RIGHT: The weather in the tropics is sunny and humid, but the breezes keep you cool.

CXI: use no comma after short introductory word groups.

A comma is unnecessary if the introductory phrase is a restrictive modifier or if there is no danger of misreading.

NO COMMA: By now her plane must have arrived.

NO COMMA: In a democracy all votes are equal.

COMMA NEEDED: By the time the plane arrived, most of the babies had stopped crying.

Do not mistake an inverted sentence, which takes no comma, for a sentence with an introductory word group. The sentence “Blessed are the meek” is the same as “The meek are blessed,” but with subject and predicate reversed.

WRONG: Blessed, are the meek.

RIGHT: Blessed are the meek.

WRONG: Beside him, stood his wife.

RIGHT: Beside him stood his wife.

The two sentences below are not inverted; they have introductory elements that require commas:

RIGHT: Blessed with talent and drive, he won a scholarship and escaped poverty.

RIGHT: Beside him, his wife stood smiling proudly.

Do not mistake an adverb modifying the main verb for a transitional (or conjunctive) adverb like “however” that modifies the entire sentence.

RIGHT (conjunctive adverb): However, I acted as if I had not noticed.

WRONG (regular adverb modifying “realized”): Immediately, I realized the truth.

RIGHT: Immediately I realized the truth.

CX.SV: use no comma between subject and verb.

An interrupting phrase or clause does not change the rule.

WRONG: The house on the hill, is haunted.

RIGHT: The house on the hill is haunted.

Nor does it matter if the interruption is long; the comma is still incorrect.

WRONG: The house that has stood vacant for decades while weeds grew in the yard, is haunted.

RIGHT: The house that has stood vacant for decades while weeds grew in the yard is haunted.

CXO: use no comma before an object, complement or list.

WRONG (object): All of us ran, the race.

RIGHT: All of us ran the race.

WRONG (complement): The waves are, perfect.

RIGHT: The waves are perfect.

WRONG (complement): It made me, sick.

RIGHT: It made me sick.

The rule applies to objects of prepositions too:

WRONG: Stephen falls into, a deep pit.

RIGHT: Stephen falls into a deep pit.

WRONG: I dance like, a baby giraffe.

RIGHT: I dance like a baby giraffe.

Do not use a comma to lead into a list or series:

WRONG: She plays all the string instruments, including, viola, cello, violin and bass.

RIGHT: She plays all the string instruments, including viola, cello, violin and bass.

CX.MP: use no comma between a modifier and the word it modifies, or after a possessive noun or pronoun.

WRONG (modifier): a deep, pit

RIGHT: a deep pit

WRONG (possessive): Homer’s, Odyssey

RIGHT: Homer’s Odyssey

CX.Ad: use no comma between cumulative adjectives.

Unlike coordinate adjectives (as in “loud, meaningless chatter”), cumulative adjectives do not modify the noun or pronoun separately, cannot be separated by “and,” and cannot be reversed. You can change “loud, meaningless chatter” to “loud and meaningless chatter” or “meaningless, loud chatter”; you cannot change “a large dining room” to “a large and dining room” or “a dining, large room.”

WRONG: three, blind mice

RIGHT: three blind mice

For more information see section C.Ad and the Grammar Tip that follows it.

CX.Conj: use no comma after a conjunction.

WRONG: Although, the weatherman predicted rain, we played the game.

RIGHT: Although the weatherman predicted rain, we played the game.

WRONG: Einstein barks at the mailman but, he does not bother prowlers.

RIGHT: Einstein barks at the mailman, but he does not bother prowlers.

CXE: use no comma before a subordinate clause or restrictive element that comes at the end of a clause.

Use no comma before a subordinate clause (beginning with words like “because,” “if” or “when”) at the end of a sentence if it is essential to the meaning of the sentence:

If the clause starts a sentence, use a comma.

Use no comma if it is at the end.

Nonessential clauses (beginning with words like “although,” “even though” and “whereas”) take commas:

Everyone enjoyed the tour, although we had to cancel some stops due to rain.

Use no comma before restrictive elements, especially relative clauses beginning with “that,” “which,” “who,” “whom” and “whose.” The correct versions of the sentences below imply “the only one who did it” and “only lions with manes”:

WRONG: I am the one, who did it.

RIGHT: I am the one who did it.

WRONG: Lions, with manes, are male.

RIGHT: Lions with manes are male.

For more information on restrictive elements, see C.Wh.

CX.Th: use no comma before indirect statements or quotations (usually introduced with “that”).

WRONG: He said that, I could leave.

RIGHT: He said that I could leave.

CXQ: use no comma before certain quotations.

If a quoted passage is not introduced by a word like “says” or “replied,” it usually needs no comma, especially if the word that introduces it is “is” or “that.” Compare the rules under Colons.

WRONG: The only rule is, “Do your best.”

RIGHT: The only rule is “Do your best.”

WRONG: He believes that, “Less is more.”

RIGHT: He believes that “Less is more.”

WRONG: He believes, “Less is more.”

RIGHT: He believes “Less is more.”