Study vocabulary from this article
Use flashcards with SRS system for long-term retention
In my experience teaching ESL, the biggest breakthrough students make with sentence structure comes when they master subordinating conjunctions. These small words do heavy lifting: they transform choppy, repetitive writing into smooth, sophisticated prose. The truth is, most learners can recognize them, but they struggle with placement and punctuation — and that’s exactly what we’ll fix today.
A subordinating conjunction is the connector that turns a simple independent clause into a dependent clause and links it to another clause. You’ll covers the nine most common subordinating conjunctions, how to use them without creating run-ons or fragments, and the crucial punctuation rules that catch even native speakers off guard.
Key Takeaways
- Subordinating conjunctions connect dependent to independent clauses — they make one idea rely on another for complete meaning.
- Common types: time, cause-and-effect, contrast, and condition — each signals a different relationship between ideas.
- Placement matters: if the dependent clause comes first, use a comma — “Before I finish, I’ll check your work.” No comma if it comes second: “I’ll check your work before I finish.”
- Avoid run-ons by using ONE conjunction per complex sentence — stacking multiple subordinating conjunctions confuses readers.
- Do not confuse with coordinating conjunctions (and, but, or) — coordinators join equal clauses; subordinators make one clause dependent on the other.
What Are Subordinating Conjunctions?
A subordinating conjunction is a word that joins a dependent clause (also called a subordinate clause) to an independent clause . The dependent clause cannot stand alone as a complete sentence; it needs the independent clause to make sense.
Example: “Although I love chocolate, I try not to eat it every day.” The word “although” is the subordinating conjunction. The phrase “I love chocolate” is the dependent clause — it depends on the main clause to feel complete.
Subordinating conjunctions show the relationship between two ideas. They might express time (“when”), cause (“because”), contrast (“although”), or condition (“if”). This relationship is what transforms a list of facts into flowing, connected prose.
Types of Subordinating Conjunctions
Time Conjunctions
Time subordinating conjunctions show when one action happens in relation to another. These include: after, before, when, while, since, as soon as, whenever, until.
Example 1: After I finish my homework, I will watch television.
Example 2: While I was cooking dinner, my cat knocked over a vase.
Example 3: Since it started raining, we’ve stayed indoors.
Cause-and-Effect Conjunctions
These conjunctions explain why something happens. The most common are: because, since, as, so that.
Example 1: Because I was running late, I missed my train.
Example 2: Since it’s your birthday, we’re going out for dinner tonight.
Example 3: I set an alarm so that I wouldn’t oversleep.
Contrast Conjunctions
Contrast subordinating conjunctions show when two ideas are in opposition. These include: although, even though, while, whereas, though.
Example 1: Although it was raining, John went for a walk.
Example 2: Even though he’s rich, he isn’t happy.
Example 3: While I prefer tea, my sister prefers coffee.
Condition Conjunctions
Condition conjunctions introduce a situation that must be true for something else to happen. Common ones: if, unless, provided that, in case, as long as.
Example 1: If it rains, we will stay indoors.
Example 2: Unless you study hard, you will fail the exam.
Example 3: As long as you finish your work, you can go out and play.
The Role of Subordinating Conjunctions in Writing
Subordinating conjunctions serve two critical purposes:
- They create complex sentences. A complex sentence contains one independent clause and at least one dependent clause. This structure allows you to express nuance and add depth to your writing without creating a list of choppy sentences.
- They signal the relationship between ideas. Instead of forcing the reader to guess how two statements connect, a subordinating conjunction makes the logic clear and explicit.
Compare these two versions:
Without subordinating conjunctions: “I studied for three hours. I still failed the test.”
With a subordinating conjunction: “Although I studied for three hours, I still failed the test.”
Notice how the second version makes the relationship clear—the effort (studying) is set in contrast with the outcome (failing).
Punctuation Rules with Subordinating Conjunctions
This is where many learners trip up. Here are the two essential rules:
Rule 1: Comma After a Dependent Clause That Comes First
If your dependent clause comes at the beginning of the sentence, always place a comma after it before the independent clause:
✓ Correct: Before I go to bed, I always brush my teeth.
✓ Correct: Although it was raining, we still went for a walk.
✗ Incorrect: Before I go to bed I always brush my teeth.
Rule 2: No Comma If the Dependent Clause Comes Second
If your dependent clause comes at the end of the sentence, you typically do not need a comma:
✓ Correct: I always brush my teeth before I go to bed.
✓ Correct: We still went for a walk although it was raining.
Note: Some style guides add a comma before “although” or “though” at the end if they introduce a strong contrast, but this is optional and less common in modern writing.
Common Mistakes and How to Avoid Them
✗ Incorrect: “Because I was tired so I went to bed early.”
✓ Correct: “Because I was tired, I went to bed early.”
Why: Do not use both a subordinating conjunction (“because”) and a coordinating conjunction (“so”) in the same clause. Choose one.
✗ Incorrect: “I will go to the store, after I finish my homework.”
✓ Correct: “After I finish my homework, I will go to the store.” OR “I will go to the store after I finish my homework.”
Why: Do not place a comma before a subordinating conjunction when the dependent clause comes second. Save commas for when the dependent clause comes first.
✗ Incorrect: “Although it was raining. We still went for a walk.”
✓ Correct: “Although it was raining, we still went for a walk.”
Why: A dependent clause introduced by a subordinating conjunction cannot stand alone as a sentence. You must join it to an independent clause with a comma.
Sample Dialogue
In a writing workshop
Student: I wrote “Because I finished early so I left the office.” Is that right?
Teacher: Not quite. You have two connectors fighting for the job. Either say “Because I finished early, I left the office” or “I finished early, so I left the office.” Pick one.
Student: Got it. So “because” and “so” can’t both be in the same clause?
Teacher: Exactly. A good way to remember: subordinating conjunctions and coordinating conjunctions have different jobs. Don’t double up.
Common Subordinating Conjunctions at a Glance
| Conjunction | Type | Meaning/Use | Example |
|---|---|---|---|
| After | Time | Shows one action follows another | After I finish my work, I’ll call you. |
| Although | Contrast | Shows contrast between two ideas | Although it’s late, I’m not tired. |
| Because | Cause-and-effect | Explains the reason for something | Because I was late, I missed the opening. |
| Before | Time | Shows one action comes before another | Before you leave, check your bag. |
| If | Condition | Introduces a condition or possibility | If you study, you will pass. |
| Since | Time or Cause | Shows time or reason | Since you arrived, everything’s been better. |
| Unless | Condition | Shows a negative condition | Unless it rains, we’ll go hiking. |
| While | Time or Contrast | Shows simultaneous actions or contrast | While he was reading, she was cooking. |
| When | Time | Shows the time of an action | When the bell rang, we left class. |
Quick Quiz
Choose the best subordinating conjunction for each sentence. (Each blank can have more than one correct answer.)
- ________ I arrived at the party, everyone had left. (After / Before / When)
- ________ he had finished his homework, he went to bed. (After / Although / Before)
- I won’t go outside ________ it stops raining. (unless / if / because)
- ________ I’m very tired, I still enjoy my job. (Although / Because / If)
- She will arrive ________ you finish the report. (because / before / after)
Answers: 1. After or When · 2. After · 3. unless · 4. Although · 5. before or after (depending on intended meaning)
Try This: Rewrite in Your Own Words
Take one sentence from the examples above (e.g., “After I finish my homework, I will watch television”). Now rewrite it using a different subordinating conjunction and adjust the meaning. For example: “Whenever I have free time after finishing homework, I watch television.”
Practice like this helps you internalize the structure and feel comfortable moving the dependent clause to the front or back of the sentence.
Related Articles
- ↑ Master Pillar: English Grammar
- How to Fix Run-On Sentences
- ↑ Back to pillar: English Sentence Structure
Frequently Asked Questions
Can I use more than one subordinating conjunction in a sentence?
Yes, but use caution. Multiple subordinating conjunctions are possible in very long sentences, but each adds complexity. Most effective sentences have one. If you want to show multiple relationships, consider breaking it into two sentences instead.
What is the difference between a subordinating conjunction and a coordinating conjunction?
A subordinating conjunction connects a dependent clause to an independent clause, making one clause rely on the other. A coordinating conjunction (and, but, or, nor, for, yet, so) connects two independent clauses of equal importance. Never use both in the same clause — choose one.
Why do we need subordinating conjunctions if we can just write separate sentences?
Subordinating conjunctions allow you to show the exact relationship between ideas and create more sophisticated, flowing prose. Separate sentences work, but they sound choppy and fail to signal how the ideas connect.
Do I need a comma before a subordinating conjunction at the end of a sentence?
Usually no. Use a comma before a subordinating conjunction at the beginning of a sentence (“Because I was tired, I left early”), but not at the end (“I left early because I was tired”). The exception is a strong contrast with “although” or “though” — some writers add a comma, but it’s optional.
Which subordinating conjunctions are most commonly used?
The “big five” are: because (cause), if (condition), when (time), although (contrast), and while (time or contrast). If you master these, you’ll handle the majority of situations in everyday English.
How do I know if a clause is dependent or independent?
An independent clause has a subject and a verb and can stand alone as a sentence. A dependent clause also has a subject and a verb, but it cannot stand alone — it relies on another clause for complete meaning. If a clause begins with a subordinating conjunction, it is dependent.
Quick Test: Check Your Understanding
5 questions to test what you've learned. No sign-up required.