Although commas are small, they are considered mighty in the realm of punctuation. Especially in academic writing, they play a crucial role in clarity and communication. In terms of clarity, they ensure to convey the correct meaning, incorporate necessary pauses, and separate ideas. Understanding the use of commas before “then”, is not only about adhering to the rules, but also about improving precision and readability.
When to place a comma before “then”
Depending on the role, “then” takes on in a sentence structure, placing a comma before “then” may be necessary. Some of the most common scenarios for when a comma is due, is when “then” functions as a coordinating conjunction to separate two independent clauses, follows a conditional clause (if/then statement), acts like an interjection, or is part of a series. Additionally, it is also necessary to place a comma before “then” when it introduces non-essential or parenthetical information in a sentence.
The word “then” primarily acts as an adverb, meaning “next,” “at that time,” “in that case,” or “besides.” When it is used in a sentence with that meaning, it is typically placed within a sequence of events and does not connect two independent clauses but an independent clause to a subordinating clause. In these cases, “then” functions as a subordinating conjunction, and no preceding comma is needed. When “then” has a temporal meaning, indicating a specific time in a sentence, a comma prior to “then” is also omitted. Following an imperative construct, the comma before “then” must also be left out. In rare cases, “then” functions as an adjective, modifying a noun, where there is no comma due before it. Lastly, when “then” stands at the end of a sentence, there is typically no pre-comma placed.
Comma
Coordinating conjunction
Conditional clause
Non-essential information
Part of a series
No comma
Subordinating conjunction
Temporal meaning
Following an imperative
Modifying a noun
At the end of a sentence
Depending on the Style Guide, comma rules may vary. Therefore, it is imperative to always check with the guidelines for the Style Guide that is followed to keep consistency in your paper. Essentially, always consider whether the sentence is clearer with or without a comma and conveys the correct meaning.
Comma before “then”
As mentioned above, a comma before “then” is placed when “then” acts as a coordinating conjunction, follows a conditional clause, introduces non-essential information in a sentence, functions as an interjection, or is included in a series.
Coordinating conjunction
“Then” does not represent a standard coordinating conjunction like “but” or “and.” However, when it acts similar to a coordinating conjunction, it typically connects two independent clauses in a series. Independent clauses are sentence structures that can stand alone and don’t need additional structures to convey a complete meaning. In this case, it is crucial to place a comma before “then” for clarity and to ensure an obvious separation between these two clauses.
Examples
- They watched the sunset, then they began to walk home.
- She finished her tasks, then she shut down her computer.
- He studied all night, then he slept all day.
Conditional clause
Conditional clauses are typically if/then statements, communicating a cause-and-effect relationship in a sentence. In these cases, the if-clause outlines a condition, while the then-clause outlines the consequence of this condition. When “then” connects conditional clauses, you must place a preceding comma.
Examples
- If he meets the deadline for the project, then he’ll get promoted.
- If they win this match, then they will advance to the finals.
- If she agrees to the terms, then they can proceed with the contract.
Non-essential information
When “then” introduces non-essential information, also called a parenthetical, in a sentence, the general rule of setting it off by commas is followed. Non-essential information can be left out in a sentence without changing the complete meaning of it. Interjections are types of a parenthetical, and are also generally set off by comma placements from the rest of the sentence. This rule also applies when “then” functions as one. As an interjection, “then” usually implies a surprising reaction, conclusion, turn of events, or impatience.
Examples
- Do you want to join anyway? Ok, then, we’ll wait for you.
- You finished your task? Great, then, we can move on to the next one.
- Do you disagree? Well, then, let’s try another approach.
Part of a series
When the word “then” is involved in a sequence of events, a comma before “then” is placed to make a clear separation. This rule coincides with the overall rule of separating elements or items in a list with commas.
Examples
- He plans to finish cleaning, then prepare dinner, and afterward, go to sleep.
- Start by preheating the oven, then prepare the dough, and lastly, bake for 10 minutes.
- We will research, then gather the data, and finally, make an analysis.
No comma before “then”
There is no preceding comma before “then” when it acts as a subordinating conjunction, introduces a dependent clause, indicates a past or future point in time, follows an imperative, functions as an adjective, or stands at the end of a sentence.
Subordinating conjunction
When “then” introduces a subordinating clause, it functions similar to a subordinating conjunction. Subordinating clauses are dependent clauses, as they can’t stand alone to have a complete meaning. Typically, they are linked with independent clauses. In these cases, there is no comma set before “then.”
Examples
- She ate a whole pizza then drank three milkshakes.
- We drank many cocktails then passed out on the couch.
- He stayed up all night then took a nap the next day.
Temporal meaning
When “then” has a temporal meaning to it, it refers to a time-related sequence or a point in time and there is no comma placed prior to it.
Examples
- He studied first and then took the exam. (Sequence)
- She was much younger then and full of ambition. (Point in time)
- He was more dedicated back then and performed better. (Point in time)
Following an imperative
When “then” follows an imperative statement or phrase, meaning an instruction or command, the overall rule is not to place a comma before.
Examples
- Turn right at the crossing and then you will see the building.
- Preheat the oven first and then put in the cookies to bake.
- Finish your homework and then start watching TV.
Modifying a noun
When “then” functions as an adjective, modifying a noun, it usually describes a specific condition or state at a past point. On this rare occasion, you don’t place a comma before “then.”
Examples
- The company’s then CEO started this impactful project.
- Located in city centre, their then headquarters was a historic building.
- The reforms were implemented by the then President, John Smith.
At the end of a sentence
“Then” at the end of a sentence often serves as a concluding adverb, implying sequence or time. Since it is placed at the end position of a sentence, it does not separate any sentence structures or clauses, hence, no pre-comma is needed.
Examples
- Study diligently and you will see the results then.
- They were planning to meet tomorrow; He’ll give her the book then.
- Let’s leave it until tomorrow; we will do the rest then.
Test yourself!
Practice sheet
Use this practice sheet to check your understanding of whether to use a comma before “then” or not. Find the correct answers in the second tab.
- If you finish your dinner you can have dessert then.
- She worked late into the night then she finished her report.
- You need to save your document then you won’t lose your work.
- He said he would call me at eight; I’ll know more then.
- We will go to the supermarket then we’ll head to the bank.
- They planned to watch a movie then go out for ice cream.
- If you’re going to the post office can you mail this package then?
- We were so young then and full of ambition.
- Check the instructions first then start the installation process.
- It was sunny in the morning; we went for a walk then.
- If you finish your dinner you can have dessert then. (No comma)
- She worked late into the night, then she finished her report. (Comma)
- You need to save your document, then you won’t lose your work. (Comma)
- He said he would call me at eight; I’ll know more then. (No comma)
- We will go to the supermarket, then we’ll head to the bank. (Comma)
- They planned to watch a movie then go out for ice cream. (No comma)
- If you’re going to the post office, can you mail this package then? (No comma)
- We were so young then and full of ambition. (No comma)
- Check the instructions first, then start the installation process. (Comma)
- It was sunny in the morning; we went for a walk then. (No comma)
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FAQs
There are various scenarios when a comma before “then” is necessary in a sentence. The following scenarios are elabourated on in this article:
- When “then” acts as a coordinating conjunction
- When “then” links two conditional clauses
- When “then” introduces non-essential information or interjects
- When “then” is included in a series
The Chicago Manual of Style (CMOS) adheres to the standard English punctuation rules in the case of using a comma before “then.” You can follow the general guidelines of comma placement before “then” delved into in this article.
Yes, place a comma before “then” in an if/then statement. In this case, two conditional clauses are connected, where the comma makes a clear separation between cause and effect.
The word “then” is versatile and has a range of usages. Depending on the context, it can have the following meanings.
Then can refer to…
- a specific time in the past or future
- a sequence of events or the next action in a sequence
- a result of a previous condition
- comparison or introducing a conclusion
- an adverb, meaning “in addition,” or “also.”
