A subordinating conjunction is a word or phrase that connects a dependent clause to an independent clause and shows a relationship such as time, cause, condition, contrast, purpose, or comparison. Common examples include because, although, if, when, unless, before, after, while, and since. The dependent clause cannot express a complete thought by itself.
Key Facts
A subordinating conjunction turns a clause into a dependent clause.
An introductory dependent clause is normally followed by a comma.
A dependent clause after an independent clause usually needs no comma.
Because, although, if, when, and unless are among the most useful everyday subordinators.
A subordinating conjunction expresses a relationship, while a coordinating conjunction joins grammatical equals.
A clause beginning with because, although, or if is a fragment when it appears alone.
What Is a Subordinating Conjunction?
A subordinating conjunction introduces a dependent clause and explains how that clause relates to the sentence’s main idea. In We stayed inside because it was raining, the independent clause is We stayed inside, while because it was raining gives the reason and depends on the main clause for a complete meaning.
The central structure is:
Independent clause + subordinating conjunction + dependent clause
Examples:
- I called Maya because I needed advice.
- Although the road was icy, the bus arrived on time.
- We will start when the manager arrives.
- Unless the alarm rings, remain in the building.
A dependent clause still contains a subject and a verb. The word because, however, signals that the clause expresses a supporting circumstance rather than a complete assertion. Compare The store closed with because the store closed. The first is independent; the second leaves the reader waiting for the main result.
Independent and Dependent Clauses
| Clause | Subject and verb | Complete thought? | Example |
|---|---|---|---|
| Independent clause | Yes | Yes | The children laughed. |
| Dependent clause | Yes | No | because the clown arrived |
| Independent clause | Yes | Yes | We left early. |
| Dependent clause | Yes | No | although the meeting continued |
| Phrase | Not always | No | after the meeting |
The distinction matters because punctuation depends on clause status, not simply on the presence of a conjunction. After dinner is a prepositional phrase, while after we ate dinner is a dependent clause.
Complete Subordinating Conjunctions List
The following list groups common subordinators by the relationship they express. Some items have more than one meaning, so the example determines the category.
Time Subordinators
Time conjunctions place one event before, after, during, or at the same time as another event.
| Conjunction | Time relationship | Example |
|---|---|---|
| after | Later than | We left after the rain stopped. |
| as | During the time that | As I walked home, the lights came on. |
| as soon as | Immediately after | Call me as soon as you arrive. |
| before | Earlier than | Wash the dishes before you leave. |
| once | After a condition occurs | Once the files upload, we can begin. |
| since | From a past time until now | Since Omar moved, we have emailed weekly. |
| till | Up to the time that | Wait here till the doctor calls. |
| until | Up to the time that | The shop is closed until the owner returns. |
| when | At the time that | When spring arrives, the garden changes. |
| whenever | Every time that | Whenever the bell rings, students switch rooms. |
| while | During the time that | While the coffee brews, I will prepare breakfast. |
Since creates a frequent ambiguity. In Since Ana left, the office has been quiet, it usually means “from the time Ana left.” In Since Ana was ill, she stayed home, it may mean “because Ana was ill.” Use ever since for time and because for an unmistakable cause.
Cause and Reason Subordinators
Cause conjunctions answer why the main-clause action occurs.
| Conjunction | Meaning or register | Example |
|---|---|---|
| as | Because; often formal or context-dependent | As the road was flooded, we turned back. |
| because | Direct reason | The flight was delayed because fog covered the runway. |
| given that | Considering the fact that | Given that demand is low, production will pause. |
| inasmuch as | Because; highly formal | Inasmuch as the contract expired, renewal was required. |
| now that | Because a new situation exists | Now that the test is complete, results can be reviewed. |
| seeing that | Because it is evident that | Seeing that the gate was locked, we used another entrance. |
| since | Because; potentially ambiguous | Since the server failed, the website is offline. |
Because is usually the clearest choice in professional writing. Inasmuch as is grammatical but uncommon outside legal, regulatory, or deliberately formal prose.
Condition Subordinators
Conditional conjunctions state a requirement, possibility, exception, or hypothetical situation.
| Conjunction | Condition type | Example |
|---|---|---|
| assuming that | Hypothetical premise | Assuming that traffic is light, we will arrive by six. |
| as long as | Requirement or limitation | You may borrow the car as long as you refuel it. |
| even if | Condition that will not change the result | We will proceed even if the forecast worsens. |
| if | Open or possible condition | If the package arrives today, call me. |
| in case | Precautionary condition | Save the receipt in case you need a refund. |
| on condition that | Explicit requirement | The tenant may sublet on condition that the owner agrees. |
| provided that | Formal requirement | Access is allowed provided that visitors sign in. |
| unless | Negative condition, meaning “if not” | Unless you hurry, you will miss the train. |
| whether | Alternative possibility or uncertainty | We must decide whether the proposal is practical. |
Unless normally means if not, but it should not replace every negative conditional. Unless the key fits, the lock will not open is logical. Unless you do not agree creates a confusing double negative and usually needs revision.
Contrast and Concession Subordinators
Concession conjunctions introduce an idea that conflicts with, or fails to prevent, the main-clause result.
| Conjunction | Relationship | Example |
|---|---|---|
| although | Formal concession | Although the route was longer, it was safer. |
| even though | Strong or factual concession | Even though the machine was old, it worked reliably. |
| though | Flexible, often conversational | Though the task was difficult, Lina finished it. |
| whereas | Direct contrast | The north side is wooded, whereas the south side is open. |
| while | Contrast rather than time | While Ben prefers tea, his sister drinks coffee. |
While can express time or contrast. In While I cooked, Ben set the table, the events overlap. In While Ben prefers tea, his sister drinks coffee, the clauses are contrasted. Context supplies the meaning.
Purpose, Result, and Manner Subordinators
Many grammar lists omit these relationships, although they are important in actual writing.
| Conjunction or phrase | Relationship | Example |
|---|---|---|
| as if | Manner or appearance | He speaks as if he knows the answer. |
| as though | Manner or appearance | The roof shook as though a storm had arrived. |
| so that | Purpose or intended result | She whispered so that the baby would not wake. |
| in order that | Formal purpose | The data were encrypted in order that privacy be protected. |
| such that | Result or degree, usually formal | The error was such that the calculation had to be repeated. |
So that often introduces purpose when the main clause includes an intentional action. In The storm was so severe that flights were canceled, so…that expresses result, not purpose.
Comparison and Alternative Subordinators
Comparison structures require special care because some are not simple one-word subordinating conjunctions.
| Form | Function | Example |
|---|---|---|
| as…as | Equal comparison | The second test was as difficult as the first was. |
| than | Unequal comparison | The river is wider than it appears. |
| rather than | Preference or alternative | I would walk rather than wait. |
| whether | Alternative or uncertainty | Tell us whether the figures are accurate. |
Than may introduce a clause whose subject or verb is understood: Mira runs faster than her brother does. The word does makes the comparison structurally clearer, although than her brother is common in informal writing.
How Do Subordinating Conjunctions Work?
A subordinating conjunction changes the grammatical status of the clause that follows it. The clause still has a subject and verb, but it becomes an adverbial dependent clause that modifies the independent clause’s time, reason, condition, contrast, purpose, or manner.
Consider:
- The match was canceled.
- Because the field was flooded, the match was canceled.
- The match was canceled because the field was flooded.
In sentence 2, the reason comes first and receives a comma boundary before the main clause. In sentence 3, the main clause comes first, and the final reason is closely attached to it.
A useful editing test is to remove the subordinate clause. If the remaining words form a complete sentence, the structure is probably sound:
- Although the price increased, customers continued ordering.
- Remove the subordinate clause: Customers continued ordering.
- Result: complete independent clause.
Where Does the Comma Go?
Place a comma after an introductory dependent clause, but usually omit the comma when a restrictive dependent clause follows the independent clause.
| Word order | Correct punctuation | Example |
|---|---|---|
| Dependent clause first | Comma after dependent clause | If the weather improves, we will leave. |
| Independent clause first | Usually no comma | We will leave if the weather improves. |
| Contrastive final clause | Comma may clarify contrast | We will leave, even if the weather worsens. |
| Two independent clauses | Subordinator does not replace a complete main clause | We left because the gate closed. |
The default rule is simple:
- Although the room was small, it felt comfortable.
- The room felt comfortable although it was small.
The second sentence normally has no comma because the final clause supplies essential information about why the room felt comfortable. Some editors add a comma before a long, strongly contrasted, or potentially confusing final clause, particularly with even though, although, or while. The comma then reflects emphasis or readability, not the basic rule.
Can a Subordinating Conjunction Begin a Sentence?
Yes. A subordinating conjunction can begin a sentence when the dependent clause is followed by an independent clause.
- Because the deadline changed, we revised the schedule.
- When the lights turn green, cross the intersection.
- Although the evidence was incomplete, the committee voted.
Beginning with a dependent clause foregrounds the condition, reason, or contrast. Ending with the dependent clause usually gives the independent clause greater emphasis.
Do not confuse a sentence beginning with a dependent clause with a fragment:
- Fragment: Because the deadline changed.
- Complete sentence: Because the deadline changed, we revised the schedule.
Which Conjunction Should You Choose?
Choose according to the exact relationship, then check whether the word creates ambiguity or an unsuitable level of formality.
Because, Since, or As?
Use because for a direct reason, since for elapsed time or a reason that the context makes obvious, and as for simultaneous action or a relatively formal reason.
- Reason: We postponed the launch because testing was incomplete.
- Time: Since testing began, the error rate has fallen.
- Simultaneous action: As the sun rose, the temperature increased.
Replace since or as with because when readers could interpret the clause temporally. This is a practical clarity rule, not a requirement that every sentence avoid multiple meanings.
Although, Even Though, or Though?
Use although for neutral formal prose, even though for a stronger concession, and though for conversational writing or a shorter sentence.
- Although the evidence was limited, the conclusion was reasonable.
- Even though the evidence was limited, the team approved the plan.
- Though the evidence was limited, the plan worked.
Do not combine although with but in the same clause structure. Write Although the fee increased, customers stayed, or The fee increased, but customers stayed, not Although the fee increased, but customers stayed.
If, Unless, or Provided That?
Use if for a possible condition, unless for a negative condition, and provided that for an explicit requirement.
- If the sensor detects heat, the fan starts.
- Unless the sensor is reset, the warning remains.
- The system will operate provided that the battery is charged.
These forms differ in logic. If the battery is charged allows one condition among several possibilities. Provided that the battery is charged presents the condition as a stated prerequisite.
Subordinating Conjunctions Compared With Other Connectors
Subordinating conjunctions are not interchangeable with coordinating conjunctions or conjunctive adverbs. The three groups create different relationships and require different punctuation.
| Connector type | Examples | Relationship | Typical punctuation |
|---|---|---|---|
| Subordinating conjunction | because, if, although | Unequal clause dependency | Comma often depends on clause order |
| Coordinating conjunction | and, but, or, so | Equal grammatical status | Comma before conjunction joining independent clauses |
| Conjunctive adverb | however, therefore, consequently | Sentence-level transition | Period or semicolon plus comma |
| Preposition | because of, despite, during | Noun or noun phrase link | No dependent clause directly follows |
Compare the meanings:
- The road flooded because rain continued. Reason is subordinate.
- Rain continued, so the road flooded. The two clauses are coordinated.
- Rain continued; therefore, the road flooded. The transition is expressed by a conjunctive adverb.
- The road flooded because of continued rain. The preposition because of takes a noun phrase, not a clause.
However is not a subordinating conjunction. Incorrect: However the road was flooded, we continued. Correct: Although the road was flooded, we continued, or The road was flooded; however, we continued.
What Are the Most Common Errors?
The most frequent problems involve fragments, misplaced commas, ambiguous meanings, and mismatched conjunctions.
Error 1: Leaving a Dependent Clause Alone
- Incorrect: Although the machine was new.
- Correct: Although the machine was new, it failed during testing.
A dependent clause needs an independent clause unless it appears as an intentional fragment in dialogue, advertising, or literary prose.
Error 2: Adding a Comma Before Every Subordinator
- Usually incorrect: We canceled the trip, because the forecast worsened.
- Standard correction: We canceled the trip because the forecast worsened.
The final reason is closely connected to the main clause. Retain a comma only when the writer has a deliberate contrast, interruption, or readability reason.
Error 3: Creating a Double Negative With Unless
- Confusing: Unless you do not submit the form, the request will fail.
- Clear: Unless you submit the form, the request will fail.
- Alternative: If you do not submit the form, the request will fail.
Error 4: Confusing Despite With Although
Despite and in spite of are prepositions, so they take a noun phrase or an -ing form. Although introduces a finite clause.
- Despite the delay, we continued.
- Despite being delayed, we continued.
- Although the train was delayed, we continued.
Incorrect: Despite the train was delayed, we continued.
Error 5: Using a Conjunction That Does Not Express the Intended Logic
- Cause: We stayed because the storm continued.
- Contrast: We stayed although the storm continued.
- Condition: We stayed if the storm continued.
- Time: We stayed until the storm ended.
Replacing one conjunction with another can change the claim, not merely the style.
A Five-Step Editing Method
Use this process to check any sentence containing a suspected subordinating conjunction.
- Underline the conjunction. Identify the word or phrase introducing the clause.
- Mark both clauses. Find each subject and finite verb.
- Test independence. Read the clause without the subordinator and ask whether it expresses a complete thought.
- Name the relationship. Label it time, cause, condition, contrast, purpose, result, or comparison.
- Check punctuation and ambiguity. Add a comma after an introductory dependent clause, then replace as or since if readers could misread the meaning.
Example:
Since the software was updated, the reports load faster.
- Subordinator: since
- Dependent clause: Since the software was updated
- Independent clause: the reports load faster
- Relationship: time, probably
- Punctuation: comma is correct
- Clarity alternative: Ever since the software was updated, the reports load faster
The final revision is better when the writer means elapsed time rather than cause.
FAQ
Are subordinating conjunctions and dependent-clause markers the same?
They overlap, but the terms are not identical in every grammar system. Subordinating conjunctions such as because, although, and if introduce adverbial clauses, while words such as that and whether can introduce content clauses. Traditional school grammar often groups all of them under subordinators.
Is “that” a subordinating conjunction?
That is commonly classified as a subordinating conjunction when it introduces a content clause, as in I know that the plan changed. Modern grammars may call it a subordinator or complementizer because the clause functions as a noun-like complement rather than an adverb modifying the main clause.
Is “whether” a subordinating conjunction?
Yes, whether can introduce a dependent alternative or embedded question clause: We need to decide whether the bridge is safe. It does not always express a condition in the same way as if, and whether is usually preferred when the alternatives are explicit or when or not follows.
Can one sentence contain two subordinating conjunctions?
Yes. A sentence can contain multiple dependent clauses: Although the road was icy, we continued because the appointment was urgent. The first conjunction introduces a contrast clause, and the second introduces a reason clause. Each clause must attach clearly to an independent clause or another grammatically suitable structure.
What is the difference between a subordinating conjunction and a relative pronoun?
A subordinating conjunction introduces a dependent clause without serving as a clause element inside it. In I left because I was tired, because shows reason. A relative pronoun such as who, which, or that refers to a noun and performs a role inside the relative clause: The book that I borrowed was useful.
Which subordinating conjunction is best for formal writing?
Because, although, if, when, and unless are generally the clearest choices in formal writing. Use provided that, in order that, or inasmuch as only when their more specific meaning or formal register is genuinely useful. Plain wording usually reduces ambiguity and editing time.
The Bottom Line
A subordinating conjunction connects a dependent clause to an independent clause and states the logical relationship between them. Use because for reason, when or after for time, if or unless for conditions, and although or whereas for contrast. Put a comma after an introductory dependent clause, check final-clause punctuation by meaning, and use the full subordinating conjunctions list as a selection guide rather than a memorization exercise.
