Grammar
Independent and dependent clauses: connect complete ideas
When the lights went out is a clause, but it leaves a reader waiting for the rest of the idea. The lights went out can stand on its own. That difference helps you decide where a sentence needs support and punctuation.
Identify independent and dependent clauses, then use conjunctions and punctuation to combine them into clear sentences.
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. /ɔːlˈðəʊ ðə rəʊd wəz ˈbɪz.i wi əˈraɪvd ɒn taɪm/
The short answer
An independent clause has a subject and verb and makes a complete statement. A dependent clause also has a subject and verb, but it cannot stand alone because a word such as because, although, when, or if makes it depend on another idea.
Although the road was busy, we arrived on time.
Why it works: Although the road was busy needs the main clause we arrived on time to finish the meaning.
5 more examples
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The library stays open until eight on Thursdays.
This is independent because it gives a complete statement about the library.
Not this:
Becausethe library stays open until eight on Thursdays What changes: Because turns the clause into a reason that needs a main clause. -
When the rehearsal ended, the actors packed their costumes.
The main clause states what happened after the time clause.
Not this:
Whenthe rehearsal ended What changes: This dependent clause gives a time but does not tell the reader what happened next. -
Mina took the earlier bus because the roads were icy.
The independent clause gives the central action, and the because clause gives its reason.
Not this:
Because the roads were icy, Mina took the earlier bus. What changes: The same reason can come first; the comma marks the end of the opening dependent clause. -
The café was full, so we chose a table outside.
So joins two complete clauses and shows the result of the first one.
Not this:The café was full.
We chose a table outside. What changes: A full stop also separates two independent clauses correctly. -
If you save the document now, you will not lose the changes.
This independent clause gives the result of the condition.
Not this:
Ifyou save the document now What changes: The if clause states a condition and needs the result clause to complete the sentence.
Read the full guide
Start by finding the verb and asking who or what performs it. Then read the words as a complete statement. If the message feels finished, you have an independent clause. If it begins with a word that leaves a question such as when, why, or under what condition, attach it to an independent clause.
Find the subject and verb first
A clause contains a subject and a verb. In The parcel arrived this morning, parcel is the subject and arrived is the verb. In because the parcel arrived this morning, the same subject and verb are present, but because changes the job of the clause. It now introduces a reason rather than making a complete statement.
The parcel arrived this morning.
Because the parcel arrived this morning leaves the reader asking what happened as a result.
Recognise an independent clause
An independent clause works by itself because it gives a finished thought. It can be short or long. The important test is not the number of words; it is whether a reader can understand the complete message without waiting for another clause.
Our neighbours are painting their fence this weekend.
The subject is neighbours and the verb phrase is are painting. The clause states a complete event.
Can The train leaves at six stand as a sentence?
Yes. It has a subject, a verb, and a complete statement.
Recognise a dependent clause
Dependent clauses often begin with a subordinating conjunction, including because, although, when, while, if, unless, before, after, and since. These words create a relationship with another clause. Because the lift was broken gives a reason, but it does not tell the reader what someone did.
Because the lift was broken, we used the stairs.
Because the lift was broken is dependent. We used the stairs is independent and completes the message.
Relative clauses also depend on another part of the sentence. In the book that I borrowed, that I borrowed describes book. It cannot normally stand alone as a full sentence.
Place a dependent clause before or after the main clause
An opening dependent clause is followed by a comma: While the children slept, the adults cleaned the kitchen. The comma helps a reader see where the background information ends and the main statement begins.
While the children slept, the adults cleaned the kitchen.
The adults cleaned the kitchen while the children slept. In this usual order, the time clause follows the main clause and no comma is needed.
Which clause gives the central action: While the children slept or the adults cleaned the kitchen?
The adults cleaned the kitchen is the independent clause. The while clause gives the time.
Join two independent clauses correctly
Two independent clauses can remain as separate sentences. You can also join them with a semicolon when the ideas are closely related, or with a comma and a coordinating conjunction. Coordinating conjunctions include and, but, or, so, yet, for, and nor. Choose a conjunction that states the relationship you mean.
The forecast changed, but we kept the picnic plan.
The forecast changed; we kept the picnic plan. A semicolon can also connect these closely related independent clauses.
Do not join two complete clauses with only a comma. The forecast changed, we kept the picnic plan is a comma splice. Add but, change the comma to a full stop, or use a semicolon.
Edit fragments and long sentences
A dependent clause used alone is often a fragment in formal writing. After the meeting finished is not a complete sentence because it gives only a time. Add an independent clause: After the meeting finished, everyone left the room. When a sentence has several clauses, identify the main statement first and then check that every extra clause has a clear connection.
Although the shop was closing, the manager waited until the customer found her receipt.
Although the shop was closing is background contrast. The manager waited is the main statement, and until the customer found her receipt explains how long the waiting continued.
How can you repair the fragment Because I missed the bus?
Add a main clause, such as Because I missed the bus, I arrived late.
Before you go
Remember this
An independent clause can be a whole sentence. A dependent clause has a subject and verb but needs a main clause because its opening word links it to another idea. Use a comma after an opening dependent clause, and use a full stop, semicolon, or coordinating conjunction to join two independent clauses.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
Try the written questionsListening test not available yet
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Try the written questionsQuestions about "Independent and dependent clauses: connect complete ideas"
What is an independent clause?
An independent clause has a subject and a finite verb and expresses a complete thought. It can stand as its own sentence, as in The library stays open until eight on Thursdays. It can also be joined to another complete clause with suitable punctuation or a coordinating conjunction.
The library stays open until eight on Thursdays.
What is a dependent clause?
A dependent clause has a subject and verb but does not complete the message by itself. Words such as because, when, although, and if make the clause depend on a main clause. For example, When the rehearsal ended needs a statement about what happened next.
Because the library stays open until eight on Thursdays
Do I need a comma after an opening dependent clause?
In the usual pattern, yes. Put a comma after an opening dependent clause before the independent clause, as in Because the roads were icy, Mina took the earlier bus. This punctuation makes the boundary between the reason and the main statement clear.
When the rehearsal ended, the actors packed their costumes.
Can I join two independent clauses with a comma?
No. A comma alone between two complete clauses creates a comma splice. Use a full stop, a semicolon, or a comma followed by a coordinating conjunction. The café was full, so we chose a table outside uses the comma and so pattern correctly.
When the rehearsal ended
What is the difference between a clause and a phrase?
A clause contains a subject and a verb, while a phrase does not contain a full subject-and-verb structure. In the morning is a phrase. When the morning class begins is a dependent clause because it includes the subject class and the verb begins.
Mina took the earlier bus because the roads were icy.