Practice
Subordinate clauses: rules and examples
The message arrived after I had left the office. The words after I had left the office add the time, but they do not make a complete sentence by themselves. They need the main clause, The message arrived.
Identify a subordinate clause, connect it clearly to a main clause, and punctuate a fronted clause accurately.
Read and practice
Read the examples and try the written questions in this guide. Listening recordings are not available for this lesson yet.
Try the written questions
Although the road was busy, we arrived on time. /ɔːlˈðoʊ ðə roʊd wəz ˈbɪzi wi əˈraɪvd ɑːn taɪm/
The short answer
A subordinate clause cannot normally stand alone. Join it to a main clause. When the subordinate clause comes first, put a comma after it: Although the store was closed, we found help online.
Because the train was delayed, Maya called her manager.
Why it works: Because the train was delayed gives the reason. Maya called her manager is the complete main clause.
5 more examples
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We stayed inside because the rain was heavy.
This subordinate clause gives the reason for staying inside. The main clause is We stayed inside.
Not this:
The rain was heavy. What changes: This is a main clause because it can stand as a complete sentence. -
If you save the file, you can close the program.
If introduces a condition. The comma follows the opening subordinate clause.
Not this:You can close the program
if you save the file. What changes: The condition follows the main clause, so a comma is usually not needed. -
Although he was tired, Luis finished the report.
Although introduces a contrast between being tired and finishing the report.
Not this:Luis was tired,
but he finished the report. What changes: But joins two main clauses. Although introduces a subordinate clause instead. -
When the meeting ends, I will send the notes.
When introduces the time for the action in the main clause.
Not this:
The meeting endsat four o'clock. What changes: This clause is complete on its own, so it is a main clause. -
The colleague who organized the workshop sent the agenda.
This relative clause identifies which colleague sent the agenda.
Not this:
The colleague sent the agenda. What changes: The main clause gives the basic message without identifying the colleague.
Read the full guide
Start with the complete message. In Because the train was delayed, the listener still expects to hear what happened. Add a main clause: Because the train was delayed, Maya called her manager. The first clause gives the reason for the action in the second clause.
Find the complete message first
A main clause can stand by itself. It gives a complete message with a subject and a verb. A subordinate clause adds information to that message but depends on it.
The team postponed the event.
This is a main clause. It makes sense without extra words.
Because the weather changed
Does Because the weather changed tell the reader what happened?
No. Add a main clause: The team postponed the event because the weather changed.
Use joining words to see the relationship
Words at the start of a subordinate clause often show its job. Because gives a reason. If gives a condition. When gives a time. Although gives a contrast.
We took a taxi because the bus had stopped running.
Because tells us why the speakers took a taxi.
If the address is correct, the package should arrive tomorrow.
Which word introduces the condition in the second sentence?
If introduces the condition: the address must be correct for the expected arrival.
Put a comma after an opening subordinate clause
When a subordinate clause comes before the main clause, readers need a clear boundary between the two parts. Put a comma after the opening clause.
Before the store opened, several customers were waiting outside.
The comma comes after the opening time clause, not after before.
Several customers were waiting outside before the store opened.
Where does the comma go in this sentence: When the call ends we will decide?
Write: When the call ends, we will decide.
Do not add a comma to every final clause
A short essential clause that follows the main clause usually does not need a comma. The clause is closely connected to the main idea.
I will email you when I get home.
When I get home tells us the time of the email. It follows the main clause, so no comma is normally needed.
I will email you, when I get home.
Is the comma in the second sentence needed for the normal meaning?
No. Write I will email you when I get home for the usual meaning.
Recognize relative clauses
A relative clause describes a noun. It often starts with who, which, that, where, or whose. A defining relative clause tells the reader exactly which person or thing you mean.
The book that I borrowed is due next week.
That I borrowed identifies the book, so the information is essential and no commas are used.
My laptop, which I bought last year, needs a new battery.
Why are commas used around which I bought last year?
The clause adds extra information about an already identified laptop. It does not say which laptop the speaker means.
Before you go
Remember this
Find the main clause first. Then identify the subordinate clause and the relationship it adds, such as reason, time, condition, contrast, or description. Use a comma after an opening subordinate clause. When an essential subordinate clause comes after the main clause, a comma is usually unnecessary.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
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Try the written questionsQuestions about "Subordinate clauses: rules and examples"
What is a subordinate clause?
A subordinate clause, also called a dependent clause, has a subject and a verb but cannot usually form a complete sentence by itself. It joins a main clause and adds information such as a reason, time, condition, contrast, or description.
We stayed inside because the rain was heavy.
How can I identify a subordinate clause?
Look for a clause introduced by a word such as because, if, although, when, before, or while. Then check whether the words can stand alone as a complete message. If the reader still expects the main result, the clause is subordinate.
The rain was heavy.
When do I use a comma with a subordinate clause?
Use a comma after a subordinate clause when it comes before the main clause. For example, Before the store opened, several customers were waiting outside. A short essential clause after the main clause usually does not need a comma.
If you save the file, you can close the program.
Is a relative clause a subordinate clause?
Yes. A relative clause is a kind of subordinate clause that describes a noun. It often begins with who, which, that, where, or whose. Defining relative clauses identify the noun and usually have no commas; non-defining clauses add extra information and use commas.
You can close the program if you save the file.
Can a subordinate clause be a sentence by itself?
In standard writing, a subordinate clause normally needs a main clause. Because the rain was heavy leaves the reader waiting for the result. Add a complete clause, such as We stayed inside because the rain was heavy, to finish the thought.
Although he was tired, Luis finished the report.