An Independent Clause looks just like a short sentence and follows the usual English pattern for sentences:
The door opened.
We won!
I love cats.
But… while a sentence stands on its own, an independent clause sits inside another sentence.
For example, those sentences above become independent clauses when we join them to other clauses:
The door opened and Mike walked in carrying a chicken!
I’m happy because we won!
I told you before that I love cats.
Independent vs Subordinate Clauses
As well as independent clauses we also have Dependent Clauses which are more commonly known as Subordinate Clauses.
The difference between independent clauses and subordinate clauses is that subordinate clauses can’t stand on their own.
If we remove the independent clauses from those examples above we’re left with subordinate clauses which are ungrammatical when they are by themselves:
* And Mike walked in carrying a chicken!
* I’m happy because.
* I told you before that.
* an asterisk at the beginning of a sentence means it’s ungrammatical
Joining Independent Clauses
You can join several independent clauses by using a semicolon or a comma plus a coordinating conjunction (and, or, but, etc). This example shows two independent clauses joined together:
{independent clause} + and + {independent clause}
Peter arrived + and + Carl greeted him.
You can see that either of those independent clauses can stand alone as a simple sentence. In this next example we have an independent clause joined to a subordinate clause:
{independent clause} + {subordinate clause}
Carl greeted Peter + when he arrived.
Here you can see that Carl greeted Peter can stand alone as a sentence, but the clause when he arrived cannot stand alone – it does not make sense on its own.
Useful Links
Clauses in English Grammar – different sorts of clauses in English
Subordinate Clauses in English Grammar – also known as dependent clauses