Commas: Correct Usage & Basic Rules

Introduction: What is a Comma?

A comma denotes a more compact break than a period, which marks the conclusion of a sentence. A comma, which separates words, sentences, or ideas inside a sentence, is viewed by some authors as a gentle pause.

Let’s look at some of the basic rules for using a comma correctly.

Basic Rules for Using a Comma Correctly

Comma with Subject and Verb

A comma should almost never be used to separate a subject from its verb.

An incorrect example for this would be − My friend Peter, is a good painter.

The right way to put this sentence is − My friend Peter is a good painter.

Separate independent clauses with a comma

Rule: When a coordinating conjunction (and, but, yet, so, or nor, for) unites two full concepts, a comma should come before it (independent clauses).

Raja drove down the street, and then he turned left.

You can go fishing with me, or you can go to the park alone.

After an introductory sentence or phrase, comma is required

After an initial clause or phrase, a comma should be used. Readers are informed by the comma that the introductory clause or phrase has ended and the main body of the sentence is about to start.

Holding his coat in his, Rakesh walked out of the house.

Surprised by the sudden attack, the platoon moved behind the lines.

Between each item in a series, place a comma

A series is a set of three or more items that all have the same purpose and have the same structure in a phrase. To separate each item in a series, use a comma.

Reena bought apples, grapes, and oranges from the store.

To separate non-restrictive clauses, use commas

Put commas around any clauses that aren't necessary for the sentence's meaning. Non-restrictive clauses are those that are not necessary. Restrictive clauses are those that are required. Relative pronouns can be used as the first word in both restrictive and non-restrictive clauses (such as who, whom, whose, that, which). The word or pronoun that comes before a relative pronoun is referred to as such.

Kunal Kapoor, who is your favourite chef, is opening a restaurant in Bangalore.

To specify a direct address, use a comma

A speaker addresses his audience directly when he specifically specifies the individual to whom he is speaking in a sentence. Depending on where it appears in the phrase, a comma or commas are used to denote direct address.

Martha, can you please pass the salt?

Can you lend me your car, Bitopi?

To separate direct quotations, use commas

A dialogue is, by definition, a discourse between two or more parties. If the speaker in the dialogue (as opposed to the listener) is recognised, his name (or the noun or pronoun used to refer to him) and the verb he uses to describe his speaking are separated by commas.

Annie said, “I hate eating noodles.”

“I don’t like tea”, Raja said.

With dates, addresses, titles, and numerals, commas should be used

Date rules − A pair of commas are used to separate the year from the remainder of the phrase when using dates. Example:

India became an independent nation on August 15, 1947.

Addressing rules − Commas are used to separate the components of an address or place name. However, a comma does not come before a zip code.

Jawaharlal Nehru studied in Cambridge, United Kingdom.

The British Prime Minister lives at 10, Downing Street, London SW1A 2AA, United Kingdom.

Guidelines for titles − If a title appears after a name, use two commas in between the title and the rest of the phrase.

Jay Kumar, CEO, has been promoted as the Managing Director.

Numbering conventions − Comma-separated groups of three numbers, beginning on the right, should be used for numbers that are longer than four digits. A comma is not required in numbers with four digits.

3,500 [or 3500]

100,000

6,000,000

Common Mistakes in Using Comma

Some of the common mistakes in using comma are as listed below.

The use of commas before coordinating conjunctions −

Seven coordinating conjunctions are: for, and, nor, but, or, yet, and so. For example, let’s look at this sentence −

The guns fired, and the soldiers charged forward.

In this sentence the ‘and’ is connecting two independent clauses (i.e., clauses that can be used as sentences). Thus, a comma is added before and. However, for a sentence like −

The soldiers marched forward and captured the post, the clauses before and after are not independent and thus there is no need to add a comma.

Using comma in correlative conjunctions −

Correlative conjunctions are conjunctional pairings, such "not only" and "but also." The second conjunction in the pair is usually preceded by a comma, although this is incorrect.

He not only scored a century, but also set a record. [Wrong]

He not only scored a century but also set a record. [Correct]

The same principle is applicable to sentences with “either/or”.

Either you give me the book back, or buy me another one. [Wrong]

Either you give me the book back or buy me another one. [Correct]