A clause is a group of related words. A clause has both a subject and a predicate. There are two types of clauses.
Independent Clause - An independent clause can stand alone as a sentence. Here is an example: We walk to school. This sentence expresses a complete thought and can stand alone.
Dependent Clause - A dependent clause cannot stand alone as a sentence. Here is an example: when the cake is done baking This clause does not express a complete thought and cannot stand alone.
Click on the following website to take a practice quiz on recognizing types of clauses. http://www.myschoolhouse.com/courses/O/1/56.asp