In the 1970s, Schoolhouse Rocks taught grammar, among other topics, in a fun, musical fashion. If you are not familiar with "Conjunction Junction," I suggest you look it up immediately. I'll wait.
That video is a nice little introduction to the concept of conjunctions, which is to connect two pieces of information. For the purposes of this hub, I am going to just discuss it in terms of creating compound and complex sentences.
A sentence must have a subject and a verb, and it must state a complete idea. In other words, from beginning to capital letter to end punctuation, each idea must stand on its own. A simple sentence is one complete idea. It can have one subject and one verb, but it also can have multiple subjects and one verb, one subject and multiple verbs, and even multiple subjects with multiple verbs. They are all still simple subjects until a new subject is introduced with a new verb. This is when we move into compound and complex sentences.
A compound sentence is made up of two related ideas joined by a coordinating conjunction. The seven coordinating conjunctions are as follows: for, and, nor, but, or, yet, so. You can remember them with the acronym FANBOYS.
"For" indicates a reason. Emile has studied really hard for his classes, for he knows the value of education.
"And" simply joins too related ideas. Charlie looks intimidating with his new look, and it has forced people to respect him more.
"Nor" introduces a negative idea, and its structure is different from the other FANBOYS. In this country, we do not attend school for six days a week, nor do most Americans want to.
"But" contrasts two ideas. Daniel is really bad when it comes to returning phone calls, but he always has a lot to say when he does call.
"Or" introduces an alternative. We can go out and spend more money at the movie theater, or we can watch a few movies on Netflix tonight.
"Yet" introduces a surprising idea. I really don't like being in front of crowds, yet most of my life's work involves being in front of people.
"So" revolves around a cause and effect situation. My students studied more for their last test, so they did pretty well on it.
You may have noticed a few things as you read these examples. Each compound sentence was divided by a comma, and the word after the comma was always one of the FANBOYS, and that word was always lowercased. If you isolate the comma and coordinating conjunction, you see two independent sentences that can stand alone. Yet, the sentences support each other.
Before moving on to complex sentences, let's reinforce the concept of an independent sentence. An independent sentence can stand on its own without any support from other material. On the other hand, a dependent sentence cannot stand on its own. It "depends" on the rest of the sentence for it to make sense.
Enter complex sentences. The same basic principle applies, but this time, we use subordinating conjunctions. There are many more of these, but here are a few: until, because, since, even though, although, before. Starting sentences with these words often leads to dependent clauses standing alone, also referred to as fragments. However, if they are joined by an independent clause (group of words), it becomes a compound sentence. Look at the following example.
Because Charles forgot to add one of his bank withdrawals, his last check bounced.
The first half of the sentence (through withdrawals) cannot stand on its own. It needs the last part for it to be complete. Notice that after that phrase, a comma is placed. This is the rule unless the subordinating conjunction appears in the 'middle' of the sentence. Let's take the same basic idea and reword it.
Charles's last check bounced because he forgot to add one of his bank withdrawals.
The subordinating conjunction appears in the middle. Thus, no punctuation is needed.
Here are a few more examples, demonstrating both ways of using these conjunctions.
Until we learn to love ourselves, we can never really love another.
We can never really love another until we learn to love ourselves.
Becky's sleep patterns have improved since she stopped drinking Diet Coke.
Since she stopped drinking Diet Coke, Becky's sleep patterns have improved.
There are also demons known as compound-complex sentences. You will see they follow the same pattern and rules, once they are broken down.
Lucy enjoys watching reality television, and she particularly enjoys trash shows like Jerry Springer even though she doesn't like some of its participants.
She enjoys reality television in general, but there is one she likes above all others.
She enjoys Jerry Springer, but she doesn't like some of its participants.
The words "Lucy" through "Springer" create a compound sentence. "She" through "participants" is a complex sentence. Together, they create a compound-complex sentence.
Alright kids, I hope this has proven useful. As always, let me know if there's something you want clarified. Until then, go listen to the video again. You won't be able to get it out of your head.