After students have mastered the organizational structure of the simple sentence, they are ready to move on to the compound sentence, which combines two complete thoughts. I like presenting this with a math equation.
1 Complete Thought + 1 Complete Thought = 1 Compound Sentence
In short, a compound sentence is really just compounding or combining two simple sentences to make a new sentence. There a few ways we can do this.
SAMPLE LESSON
The first is to place a comma followed by a conjunction between two complete thoughts.
In this example, our first complete thought is “Michelangelo loved painting.” Our second complete thought is “he loved sculpting.” The glue that holds them together, so to speak, is “, and”.
Of course there are many other conjunctions (listed below), which are more appropriately called coordinating conjunctions, that could be used in a similar format, but the most common are and, or, but. It’s important to remember that the choice of which conjunction to use depends on the message within the sentence.
If we want to show continuation or similarity such as in the sentence above, then we use and.
If we want to show alternatives, then we use or.
If we want to show contrast, then we use but.
Another way to make a compound sentence is to place a semi-colon between two complete thoughts. This format, however, is a bit harder to pull off, so it takes a degree of trial and error to figure out when it works. Typically, students might write something like this at first.
Yes, this sentence is grammatically correct and connects two related ideas in a logical way. However, we could just as easily use the comma conjunction format and say exactly the same thing.
If we want to get the most out of the semi-colon format, then we have to imagine it offering something different than the other compound sentence formats. There should be an even more intimate or profound connection between two related ideas. Likewise, the first complete thought should lead to something bigger or more significant in the second complete thought.
Now this sentence uses the semi-colon in a much better way. The ideas are connected very deeply, and the second complete thought builds on the first.
The final way to combine two complete thoughts is to place a semi-colon followed by a conjunctive adverb followed by a comma between them.
Conjunctive adverbs (listed below) are sometimes called connective adverbs. They are commonly confused with coordinating conjunctions because their functions are so closely related. I think it’s fine to lump them in with conjunctions as long you remember the difference when it comes to diagramming.
To diagram compound thoughts connected with coordinating conjunctions and semi-colons, we stack the first thought on top of the second thought. Then, we simply draw a dotted step leading from the top verb to the bottom verb. Lastly, we write the conjunction, if there is one, on the step.
Complete thoughts connected by conjunctive adverbs are also stacked on top of each other, but instead of a dotted step, we draw a dotted vertical line connecting the top thought to the bottom thought. Place the vertical line all the way to the left, and write the conjunctive adverb like a regular adverb connected to the second verb.
SAMPLE LESSON
Much like Leonardo, Michelangelo’s (1475 – 1564) talents launched him into the forefront of Renaissance art. His work was so revered that he became the subject of two biographies during his own lifetime, which was pretty much unheard of for anyone, let alone an artist. A look at our practice sentences illustrates some of the reasons for his fame.
Scholars are unsure whether Michelangelo had help interpreting the theological aspects of his paintings. Either way, he was an artistic genius and Biblical scholar in his own right. What my students often find so incredible is that his works make complex Church doctrine feel simple and easy to understand.
What’s more, his works garner a level of contemplation that is both intellectual and prayerful, ultimately evoking wonder and awe in God Himself.