The em dash vs. comma decision all depends on the strength of your pause. If you want to keep things flowing smoothly, use a comma. But for a more forceful pause that draws attention, use an em dash.
This is the quick answer to when to use an em dash instead of a comma. The two punctuation marks can both be used to set off nonessential clauses from the rest of the sentence. The difference between em dash and comma is mainly a matter of emphasis and tone.
In this guide, you will learn:
- What each mark does
- Simple rules with examples
- Which one is safer in exams and formal writing
- Common errors to avoid
Proper punctuation will help you be clear in your writing. Also, proper punctuation is crucial if you are preparing for IELTS, OET, or PTE, as punctuation mistakes will lead to a loss of marks for you in those tests.
What is an em dash?
An em dash is a long hyphen-like, the longest dash symbol (—) that is used to create a strong interruption in a sentence. Therefore, if you have ever wondered what an em dash is, consider it a visible pause.
An em dash can do the work of three other marks:
- A comma when you want more emphasis
- A colon, to talk about something, like giving a definition for a word
- Parentheses, when you want to add an aside
Here is a simple example:
- My sister—the one who lives in Dubai—is a nurse.
The two dashes set off extra information. Commas would also work here. The dashes just make that detail stand out more.
Small habits like this are easier to fix once you know they are there. IELTS students at Tiju’s Academy begin with Base Camp, a 5-day orientation, followed by Base Check, an assessment that shows their starting level. From that point, each student knows what to work on first.
When to use a comma?
A comma is needed whenever there is a need for a slight pause to maintain the continuity of the sentence. If you are unsure about the use of commas, then you should remember that it is the common punctuation mark. There are more sentences that need commas than dashes.
These are the important comma rules.
- When listing items in a sentence
Use commas between three or more items in a sentence.
- She purchased rice, fish, vegetables, and milk.
Using a comma before “and” in a sentence is optional. It is called the Oxford or serial comma. Decide on one style and use it consistently.
- After an introductory phrase or clause
Use a comma after an introductory phrase or clause at the beginning of a sentence.
- After the test, we went home.
- As it was raining, the class commenced late.
- Before a coordinating conjunction
- A comma should precede a coordinating conjunction (and, but, or, so, yet) that links two independent clauses to form a compound sentence.
- I studied all night, but I was still nervous.
- When the extra information is set off by commas
The extra information in this case should be set off by commas.
- Dr. Meera, our family doctor, has retired.
- The hospital, which opened last year, is already full.
These four rules cover most of what you need in exam writing. At Tiju’s Academy, vocabulary and grammar improvement lessons go through them one at a time, alongside Word Savvy for vocabulary. Then, daily practice activities help the rules stick.
How to use em dash?
Em dashes can be used if you want to emphasize something, shift suddenly, or separate information that is already set apart using commas. The first thing to do in learning about em dashes is to realize that it is a special punctuation mark, not a usual one.
The following is an example of using em dashes in a sentence based on the reason why em dashes are used.
- For placing emphasis
An em dash stresses whatever comes after it.
The last thing left to do is—apologize.
- When making a sudden shift or break in thoughts
An em dash can be used when breaking off from a thought.
I was sure I had locked the door—or had I?
- To isolate a parenthetical phrase
A set of dashes can be used to contain a parenthetical phrase in a sentence.
- The outcomes—all twelve of them—came in on Friday.
- If the additional information uses commas
When the additional information within the sentence uses commas, using further commas would just confuse the reader. That’s where the dashes come in handy.
- Three subjects—maths, physics, and chemistry—are compulsory.
It is important to note that all of the above examples have something meaningful to convey. A dash will not save a bad idea. In our IELTS classes, Blank2Brilliant is the method we use to get good writing ideas.
Wondering what is the difference between an em dash and a comma? Are they not similar?
The power differs when it comes to em dash and a comma. A comma provides a soft break and makes it easy to flow through the sentence. An em dash makes for an impactful disruption to the words that surround it.
| Point | Comma | Em dash |
| Strength of pause | Light | Strong |
| Effect | Smooth and neutral | Dramatic, adds emphasis |
| Best for | Lists, clauses, everyday sentences | Asides, sudden turns, key points |
| Tone | Fits any kind of writing | More casual and personal |
| How often | As often as grammar needs | Rarely |
Look at the same sentence written both ways:
- My sister, who never cooks, made dinner today.
- My sister—who never cooks—made dinner today.
The first sentence simply reports a fact. The second one sounds surprised.
Is it fine to use an em dash instead of a comma?
Yes, in those cases where commas enclose additional information, it is possible to make such replacements. The interchangeability of commas and dashes cannot be achieved in all cases. An em dash cannot be used in a list, following an introductory phrase, and preceding a coordinating conjunction.
- Right: She brought pens, paper, and a ruler.
- Not right: She brought pens—paper and a ruler.
Thus, in this case, the application of either an em dash or a comma becomes relevant only when enclosing additional information in a sentence.
When to use em dash and not comma?
Em dash is more powerful than a comma. Just try reading the sentence. A comma stands for a brief pause. A dash implies a longer pause–one which a speaker uses before making his or her point.
The advantage of the association between punctuation and speech is that good speakers understand when to pause. In speaking sessions, Brain Spark allows the students to come up with ideas easily, while Fluent Sphere makes their speech fluent. Speaking activities with feedback will aid the students in recognizing the places where pauses will be helpful and the places where they will be problematic.
Em dash, en dash, hyphen
There are three types of punctuation marks: em dash, en dash, and hyphen, and each serves a different purpose. Hyphen joins words together, en dash denotes a range, and em dash separates sentences. They are all the same and hence get confused.
| Mark | Symbol | Length | Main job | Example |
| Hyphen | – | Shortest | Joins words or parts of words | well-known, part-time |
| En dash | – | Medium | Shows a range of numbers or dates | pages 10–15 |
| Em dash | — | Longest | Breaks a sentence to show importance | She knew the answer—finally. |
Getting the em dash vs. en dash vs. hyphen right is a small detail, but small details show care.
It is also important in reading. A dash in reading material normally means that a clarification or an example follows soon. This makes it easy for you to locate the answer. Savvy and the 40in60 program at Tiju’s Academy explain reading materials with such detail. Listenlock explains listening materials with such detail, since in listening, the pause of the speaker serves the role that punctuation serves in writing.
Em Dash vs. Semicolon, Colon, Parentheses
The em dash can sometimes substitute a semicolon, a colon, or parentheses, but each one of them has a different style. The below guidelines will help you.
Em dash vs. semicolon
A semicolon joins two complete sentences that are closely related. It is calm and formal. An em dash can join them too, with more drama.
- The rain stopped; the match began.
- The rain stopped—the match began.
In the em dash vs. semicolon choice, the semicolon is safer for formal work.
Em dash vs. colon
A colon introduces a list or an explanation. An em dash can do the same job in a more relaxed way.
- He wanted one thing: sleep.
- He wanted one thing—sleep.
For em dashes vs. colons, pick the colon in reports and essays.
Em dash vs. parentheses
Parentheses, also called round brackets, make extra information quieter. Em dashes make it louder.
- The new library (which opened in March) is always full.
- The new library—which opened in March—is always full.
With em dashes vs. parentheses, use parentheses when the detail is minor and dashes when you want it noticed.
Quickest way to remember:
- Formal and neutral: comma, semicolon, colon
- Quiet aside: parentheses
- Loud aside or emphasis: em dash
Having multiple ways to connect ideas is what the examiners refer to as range. Tiju’s Academy’s writing templates for Band 7+ require you to use the sentence patterns that use these punctuation marks properly to have the structure prepared ahead of time.
Can I use em dash in formal or academic writing?
You can use em dash in both formal or academic writing but not often. You should only have one or two em dashes throughout the whole essay. In almost all formal sentences, the comma, colon, or semicolon will serve the same purpose with a slightly different tone.
How much em dash is appropriate in formal writing? It depends on where you plan to use it:
- Academic writing and reports: mainly commas, colons, and semicolons
- Business emails: commas and a full stop will make your writing clearer
- Blogs, stories, personal letters: em dashes will be perfect
Should I use em dashes in IELTS or OET writing?
It is safer to stay away from using em dashes in IELTS and OET essays and use commas instead. The dash does not contribute anything that cannot be achieved through correct comma usage, and its incorrect usage would be an error. A handwritten exam may also cause confusion where a dash can be mistaken for a hyphen.
How it relates to each exam:
- IELTS Writing Task 2: Punctuation is evaluated during assessment according to the criterion of Grammatical Range and Accuracy, which is one of the four criteria determining your band score. Good use of commas in complex sentences demonstrates good grammar skills.
- OET letter writing: the letter is an official document addressed to a fellow healthcare professional. It is appropriate to use clear punctuation.
- PTE essay: the essay is assessed using a computer.
In the case of Tiju’s Academy, the band descriptors will be explained in very easy language by the examiners. Then they will have to go through the detailed IELTS preparation plan and target band score based on their required score. The 4-in-1 IELTS coaching program will also include exam techniques for the four sections.
It is practice that makes a rule a habit:
- Unlimited mock test series provided to students by Testfinity
- You can take the mock test in an exam-like environment
- Time management techniques will enable you to save some time to proofread your punctuation
- TenX is the special examination group at Tijus
When should I not use an em dash?
Do not use an em dash if a comma, colon, or period does the trick. Likewise, do not use an em dash in a list, in very formal texts, and in a paragraph where you have already used it once.
This is what you see most frequently:
- Use of an em dash as a replacement for all commas. An abundance of em dashes will give your writing a breathless quality.
- Usage of a hyphen (-) in place of an em dash.
- The opening of an aside with a dash and its closure with a comma. The two must complement each other.
- The use of an em dash as a band-aid on a comma splice or a run-on sentence. A period or a conjunction may work better.
A comma splice occurs when two sentences are joined using only a comma: I was tired, I went to bed. Write, “I was tired, so I went to bed.”
Number of em dashe in a sentence
Use only one or two em dashes in a sentence, or it will make the reader confused.
Is using too many em dashes a bad writing?
Yes, excessive use of em dashes affects your writing negatively. Emphasis is created through the rarity of the usage. Using them in every sentence makes everything equal and lowers readability.
Do you put spaces around an em dash?
The spacing around an em dash varies from one style guide to another. The commonly used styles regarding spacing are as follows:
- Chicago style – no space around the em dash (word—word)
- AP style – one space around the em dash (word — word)
- British vs. American English – British writers use a spaced en dash (word – word) while Americans use an em dash
Stick to one style throughout the document.
It is not easy for most people to notice their own style of punctuation. They need to be made aware by someone. This is how personalized essay correction at Tiju’s Academy works. We have our writing correction program called 250in60. The progress report will tell you if you are making the same mistake again. You can clear your doubts in the community peer group and also attend live classes.
How to type an em dash on a keyboard?
Em dashes can be typed using shortcuts on the keyboard or from a list of special characters available in the software application you use. Here are the methods for typing an em dash on each device:
| Device or app | How to type it |
| Windows | Hold Alt and type 0151 on the number pad |
| Mac | Press Option + Shift + Hyphen |
| Microsoft Word | Type two hyphens between two words and keep typing |
| Google Docs | Go to Insert, then Special characters, and search for “em dash” |
| Android or iPhone | Press and hold the hyphen key, then choose the longest dash |
If none of these work, two hyphens (–) are accepted as a stand-in in plain text.
Conclusion
A comma is used for natural pauses. An em dash, however, is used when you wish the reader to pause and pay attention. If you are unsure between the two, then use the comma. You can never go wrong with the comma.
The following are the punctuation rules in English according to this guide in brief:
- Commas should be used for listing, introductory phrases, compound sentences, and extra information.
- Use em dashes for emphasis, sudden turns, and asides that already contain commas.
- Keep dashes out of exam essays, formal letters, and business emails
- Never use more than two in one sentence
One more tip for test takers: do not try new punctuation on exam day. Use the marks you already handle well. Students hear this kind of advice in our exam-day preparation module and on Mic Drop Day, the last day before the exam.
So if you are looking for English grammar classes in Kerala as part of your exam preparation, or the best OET online training in Kerala, you are in the right place.
