A clause is simply a group of words with a verb. When a clause can stand alone, it is called an independent clause (also known as a complete sentence). When that clause does not make a complete thought, it depends on another clause to complete the thought and is called a dependent clause. This same dependent clause is sometimes called a subordinate clause because it is used to subordinate lesser ideas in a sentence. Take a look at these examples.
•Examples
John lives around the corner. He owns a ’65 Mustang. (both are independent clauses because they can stand alone).
Let’s make one of them a dependent clause. John, who lives around the corner... He owns a ’65 Mustang. Notice the first clause is no longer a complete thought. Well, why would you do that? By making one of the sentences a dependent clause, you can subordinate ideas. Decide which of the sentences is more important. Then, make the other a dependent clause and combine it with the complete sentence to make a single, complex sentence. For example…
If John’s living around the corner is most important, then subordinate the second sentence.
John, who owns a ’65 Mustang, lives around the corner.
If John’s owning a ’65 Mustang is most important, then subordinate the first sentence.
John, who lives around the corner, owns a ’65 Mustang.
See how this works? Subordinating your ideas is a powerful writing tool. For more detailed information, see the three types of clauses discussed in this site: Adjective Clauses, Adverb Clauses, Noun Clauses.
Notice: To find a subordinate clause in a sentence, follow the guidelines of Sentence Analysis. Find all the verbs in a sentence first.
•Example: I want the jacket I left in the hotel.
I want the jacket I left in the hotel. (there are two verbs that are not connected by a conjunction; therefore, one is a subordinate clause. To find out which, find the subjects and continue with the analysis).
I want the jacket I left in the hotel. (now see if you can insert a relative pronoun in front of one of the subjects).
[that] I want the jacket [that] I left in the hotel. (the first one doesn’t make sense, but the second does. That’s the subordinate clause).
I want the jacket [that]I left in the hotel.