As you learned in Chapter Two, sentence variety is crucial to good writing. Using nothing but short simple sentences makes writing seem choppy. You learned to create sentence variety with compound sentences. The compound sentence is made through coordination using one of the three methods of sentence combining covered in Chapter Two. These methods included using a comma and a coordinating conjunction to join two independent clauses (sentences), using a semicolon, using a conjunctive adverb which is punctuated with a semicolon and a comma.
In Chapter Four, you learned another method of combining sentences using subordination. Subordination changes an independent sentence into a dependent clause and joins the two sentences together to create one complex sentence. A sentence is changed into a dependent clause by adding a subordinating conjunction to the beginning of one of the sentences. The two sentences are joined together by putting the dependent clause either at the beginning or the end of the independent sentence. Chapter Five reviews these five options for sentence combining and gives you the list of all the types of conjunctions in a handy chart.