What is Punctuation in English? [an intro for academics]

This blog explains the purpose of punctuation in English, its importance in academic writing, and the most common punctuation marks used, such as the period, comma, question mark, and exclamation point. Correct usage of these marks is essential to make writing clearer and more understandable, as they help structure words, separate sentences, and indicate strong emotion or emphasis. The blog also provides examples of correct and incorrect usage of punctuation marks.

Updated on April 7, 2023

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Punctuation in English is the use of written symbols to help readers clearly understand what you’re trying to tell them. Most languages have some form of punctuation, and many now share common symbols. But in English, punctuation marks may have a different meaning or style of use.

For example, Greek uses a semi-colon (;) to indicate a question. And Japanese tends to use exclamation marks more liberally!!!

So, as a researcher who wants to publish in English, there’s great value in mastering punctuation. This will ensure your work is effective and more easily understood. In academic writing, as with your methods and your data, punctuation should be appropriate and accurate. It should remove questions from the author’s mind, and assist their understanding.

This article defines what punctuation in English is, especially in the context of academic writing. And it gives the most common kinds of punctuation and why they’re important to use, especially in academic writing. You’ll also get examples to help you master punctuation in your writing.

Definition of English punctuation

English punctuation used to be known as “pointing,” and became known as “punctuation” (from the Latin punctus) in the 1500s.

The Collins and Oxford English dictionaries note that punctuation is a way of using symbols to put words into sentences, clauses, and phrases.

Punctuation uses spaces and marks to help people read and understand text. That’s usually in the way the author intended, but in the case of poets and other creative types, punctuation may also be used to create a feeling or encourage the reader’s interpretation. Powerful!

Punctuation marks in English are signs like a period/full stop (.), comma (,), and exclamation point (!). They help writers structure their words to make sense. This can be done by pointing out the start and end of sentences or listing items in a specific order. Punctuation also acts like a script so the reader will read the text in the way the author wanted.

The most common forms of punctuation in English

These are the most common punctuation marks used in English. Use these correctly and your writing will be clearer, more logical, and more easily understood. That means more people will read it.

Period or full stop

A period (.), also called a “full stop,” indicates the end of a sentence that is not an exclamation or a question. It also marks abbreviations, though this varies by English type. U.S. English, for example, uses a period in certain cases where U.K. English does not (such as Dr. and Ph.D.).

Also note that there should be a single space after a period, not a double space. However, some people who grew up with typewriters or word processors, or who learned from an older teacher, may mistakenly use two spaces. Before PCs, a double space was used to make writing easier to read.

Correct use of the period:

Ending a sentence: Good researchers write clear manuscripts.

Marking an abbreviation (especially in U.S. English): Dr. Wong asked me to write the Methods section.

Incorrect use of the period:

Omitting the period between sentences: I wrote the Methods Dr. Wong asked me to write them.

Corrected: I wrote the Methods. Dr. Wong asked me to write them.

A period helps the reader separate ideas into different sentences. Without a period, the reader sees a long, run-on string of words with no breaks. And for abbreviations, it may be less clear that an abbreviation is actually being used.


A comma (,) has a few uses in English. Much like in this sentence, a comma separates a list of items, facts, and phrases. It is also important for quoting direct speech, addressing someone, or including additional information in a sentence.

Correct use of the comma:

Including additional information: I wrote the Methods, which hadn’t been done, for Dr. Wong.

Quoting direct speech: The student said, “Class is finished. Now it’s lunchtime.”

Separating a series of items: We’ll need time, money, and lots of patience.

Incorrect use of the comma:

Omitting a comma when a pause is needed: Let’s eat Dr. Wong.

Corrected: Let’s eat, Dr. Wong.

A comma is put where you want a brief pause in speech. It separates ideas and items that don’t need a long break or that finish a thought; that’s what a period is better for.

Without commas, the meaning of a sentence, list of words, or different thoughts can be misunderstood.

Question mark

A question mark (?) indicates the end of a sentence that is a question.

Correct use of the question mark:

A direct question: Will you add a citation here?

Someone asking a question: “Do you know what you’re doing?” Dr. Wong asked.

Incorrect use of the question mark:

Using a question mark when making a statement (because it turns it into a question): This is a grammatically complete sentence?

Corrected: Is this a grammatically complete sentence?

A question mark shows that a sentence is a question, not a statement. Leaving it out or using another punctuation mark can totally change the meaning.

Exclamation point

An exclamation point (!) indicates the end of a sentence with strong emotion or emphasis.

Correct use of the exclamation point:

Exclaiming achievement: This a great manuscript!

Expressing excitement: We are finally done! Let’s party!

Incorrect use of the exclamation point:

Adding an exclamation point to a question: Do you think this is terrific work!

An exclamation point helps stress the emotion that writing should be read with. Sometimes, better word choice is preferable to an exclamation point. Other times, careful and conservative use of exclamation points can really make your writing pop!

But keep in mind that academic manuscripts almost never need an exclamation point. Especially not in the title.

Quotation marks (single and double)

Quotation marks (“ ” or ‘ ’) show that the writer is mentioning words that someone else said or wrote. They should open (“ or ‘) at the start and close at the end (” or ’) of the other person’s words.

Single quotation marks are for quotations within double quotations in U.S. English, but the reverse is often used in U.K. English and other Commonwealth versions of English, such as Australian English.

In a completely different way, quotation marks can also be used to convey irony or sarcasm.

Examples of using quotation marks:

Quoting something someone says: Dr. Wong said, “I hope you completed that task I asked you to do.”

Quoting someone within a quote: A student repeated, “Dr. Wong said, ‘I hope you completed that task I asked you to do.’”

Adding irony or sarcasm: This isn’t a kitchen; it’s a “food laboratory.”

Incorrect use of the quotation mark:

Omitting the closing quotation mark: Dr. Wong exclaimed, “These students understand punctuation really well!’

Corrected: Dr. Wong exclaimed, “These students understand punctuation really well!”

Quotation marks help acknowledge the original author of certain words. Without them, it’s hard to be sure what words were the writer’s or someone else’s. And when you’re citing other publications, it’s critical that you indicate which words are yours and which are someone else’s. Otherwise, you may be accused of plagiarism!


A colon (:) shows that information after it will be a list, quote, summary, or explanation. It also separates units of time. There should never be a space to the left of a colon, but there should always be a single (not double!) space to the right.

Correct use of the colon:

Preceding a quote: Dr. Wong often says: “Without punctuation, words are meaningless strings of letters.”

Describing time: “We’ll go to lunch soon,” Dr. Wong said.

Incorrect use of the colon:

Adding a redundant colon: There are many punctuation marks, such as: the period, comma, and colon.

Corrected: There are many punctuation marks, such as the period, comma, and colon.

A colon guides a reader to information in a structured way. Sometimes, a comma, en-dash or em-dash (see below), or even a new sentence is more suitable. So if it’s important writing, have an editor or someone with excellent grammar review it.


A semicolon (;) separates two tightly linked clauses. It also separates items in a list where commas are used. There should never be a space to the left of a semi-colon, but there should always be a single space to the right.

Correct use of the semicolon:

Linking closely related clauses: Punctuation is important in writing; it helps readers understand your text.

Listing items with commas: Dr. Wong has lectured in Tokyo, Japan; Guangzhou, China; and Cape Town, South Africa.

Incorrect use of the semicolon:

Using a semicolon instead of a comma: Periods; commas; and question marks are punctuation marks.

Corrected: Periods, commas, and question marks are punctuation marks.

A semicolon helps when a period would separate two clauses too much. And it is like a colon, but shows the clauses are more closely related. Without a semicolon, relations between clauses may be unclear.


An apostrophe (’) shows a contraction or possession. It’s also used for the plural form of lowercase letters.

Correct use of the apostrophe:

Indicating the plural of lowercase letters: Dr. Wong always tells us to work faster.

Showing possession: This is Dr. Wong’s best research ever.

Incorrect use of the apostrophe:

Omitting an apostrophe in a contraction: Thats a good sentence.

Corrected: That’s (that is) a good sentence.

Adding an apostrophe when you don’t need one:  Our research has lost it’s way.

Corrected: Our research has lost its way.

Indicating a plural noun: Apple’s are on sale today.

Corrected: Apples are on sale today.

Apostrophes help bring words together. They also explain the relationship between objects and subjects. Without apostrophes, relations between words may be unclear.

Parentheses and brackets

Parentheses (( )) can replace commas when including additional information. Brackets ([ ]) clarify the meaning in a sentence or quote.

Correct use of parentheses and brackets:

Using parentheses to add information: Dr. Wong (our lead author) will contact the journal.

Using brackets to clarify who is being spoken about: He [Dr. Wong] also served as the corresponding author.

Incorrect use of parentheses and brackets:

Swapping brackets with parentheses: Dr. Wong asked me to evaluate the (grammatical) correctness of the other authors’ sentences.

Corrected: Dr. Wong asked me to evaluate the [grammatical] correctness of the other authors’ sentences.

Parentheses and brackets add clarity to your writing. Without them, additional information can seem out of place or interrupt the reading flow.


Ellipses (…) show that words or sentences are left out of the text. They can also add a dramatic effect or indicate continuation. Ellipses are always three periods.

Correct use of ellipses:

Building suspense: Dr. Wong entered the lab looking tired…and suddenly fell to the floor.

Indicating a partial or incomplete sentence in a quote: Punctuation is a way of using symbols…” according to the Collins and Oxford English dictionaries.

Incorrect use of ellipses:

Adding a period after ellipses: Punctuation helps a reader understand the text better if you use it well…

Corrected: Punctuation helps a reader understand the text better if you use it well…

Correct use of ellipses:

Indicating more information is coming: This video contains useful information, such as...

Ellipses save you from writing out long pieces of text that other authors have published. Without ellipses, your text could become very long or include unrelated words.

Other punctuation marks

Some less-common types of punctuation are hyphens (-) and en-dashes (–). A hyphen joins parts of a compound word, number, or name. Like brother-in-law or thirty-three. An en-dash is longer than a hyphen. It separates parts of a sentence – like this. Or it can be used to insert related, but non-vital information (similar to parentheses). Sometimes, an em-dash (—) also serves that function.

We all make mistakes... and we all can fix them

Punctuation mistakes are common among native speakers. English is a tough language, even if you grow up with it! There are so many rules. And don’t rely on grammar-correcting software to always give you good advice; it’s not perfect. It’s also frustrating when you’re trying to get published or get the OK from an adviser.

When English isn’t your first language (and even when it is), mastering punctuation can be a challenge. Some people never get it completely right. And you’ll run into peer reviewers who insist on pointing out every missing comma and misplaced apostrophe. Order an AJE expert scientific edit to have a professional editor fix your punctuation and get your entire manuscript fit for publication.

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