Comma - Definitions, Functions, Uses with Examples

Comma – Definitions, Functions, Uses with Examples

Hello there! Still on our discussions of the various punctuation marks in English, we will be looking at the comma in this post titled: Comma – Definitions, Functions, Uses with Examples. The comma is another popular punctuation mark that many people use indiscriminately without recourse to proper usage. Let us take a look at this punctuation mark…

Comma – Definitions, Functions, Uses with Examples

In looking at this punctuation mark, it will be proper to examine what a comma is before looking at its uses alongside useful illustration.

What is a Comma?

The comma accounts for over 60% of all the punctuation marks we make use of.  In other words, the comma is a versatile and often misused punctuation mark. Current usage favours the insertion of a comma only where we intend a pause.

Comma is a punctuation mark that indicates brief pauses in spoken utterances. Comma indicates a light pause and we use it mainly to separate a structural unit of a sentence, to set off confusing main clauses, parenthetical material closely related to the main thought, direct quotations, forms of direct address, coordinate adjectives and words or numbers.

When to Use a Comma

We also need to know when not to use comma in addition to knowing when to use it. Commas are vital to the meaning of all types of utterances and writings that if misused, meaning can change completely. For instance, look at these sentences below and observe how comma alters the meanings:

  • A woman without her man is nothing.
  • A woman, without her, man is nothing.
  • Let us eat grandpa.
  • Let us eat, grandpa.

Uses and Functions of the Comma

Briefly, let us see some of the major uses of the comma.

We use Commas between Coordinate Clauses

We use a comma before the conjunction that links the main clause in a compound sentence, especially when the clauses are long. For example:

  • The teachers asked the junior students to stop sneaking into the School’s sugarcane plantation, but they refused to heed their instruction.
  • Many contractors bid for the project, and the government considered a good number of them.
  • The subsidy reinvention programme of the Federal Government is not all embracing, yet it is better than not getting anything from the government.

You can see these posts to have an idea of a Coordinate Clause:

 In a Series or Listing, Commas to Separate Items

For example:

  • The Management of the institution invited the President, his Vice, the Ministers, the Permanent Secretaries, the State Commissioners and traditional rulers to its centenary celebrations.
  • I bought two loaves of bread, one pack of table water, for gallons of vegetable oil, five bags of rice, three drums of palm oil, ten tubers of yam and fifteen cartons of drinks for the widow.
  • She wanted the black, green and blue dress.

Oxford Comma Example

There is usually this debate about using or not using comma after the penultimate item in a list. This final comma, which we refer to as the Oxford or serial comma, is useful in a complex series of elements or phrases but some consider it unnecessary in a simple series such as in the examples above.

It boils down to style or choice of the writer. However, some scholars believe that in order to avoid confusion, ambiguity or misinterpretation, it is better to use the comma. For instance:

  • Groceries include vegetables, food items, wines, juices, margarine, butter, beverages, pastries, bread and butter.

They wonder if ‘bread and butter’ constitute a group or separate entities? But as noted above, everything boils down to a matter of choice.

The Use of Comma in Conventional Places

Such places where we use commas conventionally include the following:


To separate numbers in thousands, tens of thousands, hundreds of thousands, millions, billions, trillions, etc. For instance:

  • 7,500
  • 23,475
  • 726,765
  • 1,112,786
  • 17,235,400
  • 3,310,109,456


We use commas to separate the day of the month and year. For instance:

  • 21st August, 2018
  • April 4, 1986
  • July 4, 1776
  • October 1, 1960
  • February 14, 2019


To separate streets, towns, states, we use commas. For instance:

Hamilton Business School,

Lekki Phase II, Victoria Island,


Lagos State.


14, Coker Street,


Delta State.


To separate proper names from titles and degrees. For example:

  • James Newton, Snr.
  • Isaac Watts, Jr.
  • Josh Gibran, BSc, MA, PhD
  • Sir Akinruli, OBE, CON, FMNI
  • Lt. Gen. Burger, Rtd. KBE, GCON, ESQ.


If the last item in days, addresses and titles falls within a sentence, a comma follows the item. See these examples:

  • The young officer attended Royal Air Force College, London, where he graduated top of the class.
  • The explorer arrived the shores of the country February, 21, 1760, one month before he was abducted.


We use commas after the opening salutation in formal and informal letters and after the complimentary close of such letters. For instance:

  • Dear Sir,
  • Yours faithfully,
  • Dear Johnson,
  • Yours truly,
  • Dear mother,
  • Yours sincerely,

Direct Speech or Quotations

We use commas after expressions that introduce direct speech or quotations. For examples:

  • The president said, “I will not scrap NYSC.”
  • The teacher warned, “Nobody should come to school tomorrow if they have not paid their fees.”

But if the expression interrupts a sentence in the quotation, we use two commas to mark it off. See this example:

  • “Nobody should come to school tomorrow”, the teacher warned, “if they have not paid their fees.”

Read more explanations in the post on Quotation Marks.

Comma with Appositives

We delineate appositions or appositives (See the post Appositions in English for a proper understanding) by the use of commas. For example:

  • John Calvin, a leading figure in the Protestant Reformation, founded Calvinism.
  • The German theologian and religious reformer, Martin Luther, was born in Eisleben on November 10, 1483.
  • The truck driver, a chain smoker, died of acute bronchitis.
  • His beautiful wife, Lynda Mariah, received an award of recognition for her commitment towards orphans.
  • The new movie, Black Panther, grossed over $136m at its premiere.

Comma with Vocative Case or Direct Address

When we use the vocative case or direct address, we use commas to mark off the words. For instance:

  • Mr. Johnson, kindly see me tomorrow.
  • Thanks for all your assistance, Henry.
  • I subscribe, my friends, to all he said.
  • Dear students, would-be alumnus, live up to our expectations.
  • I strongly believe, my dear children, that working smart is better than working hard.

Comma with Interjections and Particles

When exclamations such as wow, oh, alas, and other particles like yes, no, in fact, etc. occur at the beginning of sentences, we use commas to mark the off as you have in these examples:

  • Yes, you are correct.
  • No, I won’t stoop that low.
  • Indeed, it was the end of an era.
  • In fact, I could not contain my surprise.
  • Really, she was impressive.

We Use Commas to set off Parenthetical Elements

There are instances in which a word, a phrase or clause interrupts the movement of thought in a sentence. When this happens, we wet such off by commas or other appropriate marks. See these examples:

  • University of Ibadan, or the Premier University as people commonly refer to it, is the first university in Nigeria.
  • There are, however, few Nigerian students in Latin American Universities.
  • As he had earlier noted, it cannot be overemphasised, Nigeria needs restructuring and true federalism, if we must move forward, though.

Other punctuation marks that we can use in place of commas in the examples above include the dash (n-dash or m-dash) and the parenthesis (brackets).

We use Commas to Mark off Subordinate Clauses

When we write some long modifying phrases and subordinate clauses that are adverbial in nature, we mark them off by commas when they come before the main clause. However, when they come at the end of the main clause, commas are not necessary. Let us consider some examples:

  • When the man noticed that his son was already asleep, he stopped rocking him.
  • Before the internet came into Nigeria, people sleep for longer hours at night.
  • Shocked by the gory sight of the accident, he decided never to take public transport again.
  • Coming into a new environment, she withdrew into her shell.
  • After the first half ended, the players were evidently tired.

Commas with Non-Restrictive Clauses and Groups

A non-restrictive clause or group does not limit or defines the item it qualifies; that is, it does not restrict or narrow down its meaning and if we decide to omit it, the meaning of the sentence in which it occurs will not be affected. (Read more under Relative Clause). We use commas to mark of the non-restrictive or non-defining relative clause in a sentence to show their subordinate function. Let us consider some examples:

  • The students, who were given admission recently, are yet to resume for academic work.
  • Members of the committee, on ethics and privileges, visited the governor.
  • The driver, who recently bought a new bus, has served the company for 20 years.
  • The challenges, which he faces constantly, are not new to him anymore.
  • Members of the team, which won the tournament, have resumed training.

Commas Indicate a Pause in a Sentence or Question

 We use comma to indicate a pause in a sentence or in a question. See these examples: 

  • Johnson, would you be at the party?
  • Thank you, Mr. Sunday.
  • Sola, it has been nice working with you.
  • Mike, did you remember to feed the chicken?
  • Smith, can you tell us the real situation?

Misuse of Commas

There are various instances where people misuse the comma. We need to know such instances and avoid making mistakes when we use the comma. I have put together a post on the misuse of commas. Check the post Instances Where People Misuse Commas to learn one or two things.

Final Words

So much to say and learn about this most versatile punctuation mark in English! I am certain you have gained some useful knowledge in this post Comma – Definitions, Functions, Uses with Examples.

You can check out other punctuation marks that I have also put together for your reading pleasure. Do not forget to share this knowledge and connect with us on our Social Media platforms. It is just a click away. See you around.

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