When writing, we always use 4 different types of sentences: simple, compound, complex or compound-complex. Simple sentences are independent clauses while compound sentences are 2 or more independent clauses. A complex sentence is an independent plus a dependent clause while a compound-complex sentence is 2 or more independent clauses plus 1 dependent clause.
Let's talk sentence types. We've got four different types of sentences, whether you know them or not, you do use them in your writing. You always use either simple, compound, complex or compound complex sentences. And here are some tricks when we are talking about identifying the types of sentences that you're using. The first is to be able to identify all the subjects and all the verbs that exist in your sentences because that's really going to be the key in determining what kind of sentences you have. The other trick, short doesn't always mean simple, so don't just default if you see a short sentence to say this is a simple sentence. And then finally variety is the spice of writing and we're going to talk about that in a little bit. But let's talk about the different sentence types first. The first sentence type that you got is a simple sentence and it is like it sounds. It contains just one independent clause. So when you're looking at the sentence "Suzy and Sally went horseback riding." You are going to identify your subject and its compound here but "Suzy and Sally" still just one subject, and what did they do? They "went horseback riding." So you got one subject, one predicate, the one independent clause, you've got a simple sentence, right? If you want to get a little bit fancier, then go to compound sentences and that's two independent clauses joined together and there is a variety of ways that you can join them. So let's take a look at this example, we've got the first sentence "Suzy and Sally", so we already said that was the subject, "went horseback riding" is a predicate, but then we've got a comma and the word "and" which is a conjunction joining that first sentence to "then they went out to dinner" we've got another subject "they" and what did they do they "went out to dinner". So we've got two independent clauses being joined by that comma and the conjunction, two independent clauses makes a compound alright. Next up we've got complex sentence types and that's when you have one independent clause added to one dependent clause so it's just a little bit of a different style. Let's take a look at this sentence "Because Suzy and Sally had been out all day, they were furnished." So if we look at this sentence, this comma kind of draws us to a split in it and what you'll notice is, this side here "they were furnished" can stand on its own. We've got a subject "they" and then we've got a full predicate "were furnished". So we've got an expression of complete thought that can stand on its own, we call that an independent clause. And if we look up here we have "Because Suzy and Sally had been out all day", now what we notice about that is it's got a subject; Suzy and Sally and it tells us what they've been doing, they've been out all day, so we've got a predicate. But we've got a subordinating conjunction here that starts it off which makes that a subordinate or a dependent clause. So when you've got a dependent hooked to an independent, you've got a complex sentence. And then finally and probably the sentence type that you will use the most sparingly, is the complex compound sentence. So it's exactly what it sounds like. It's a combination of a compound and a complex, so you've got two or more independent clauses like the compound sentence, hooked up to one dependent clause. So we've got "when Suzy and Sally ordered dinner their eyes were bigger than their stomachs, so they had lots of leftovers." So if we start looking at the splits here, we've got commas and that generally tells us that there is a split in the sentence, so we've got a comma here and here. Let's take a look at this first part "when Suzy and Sally ordered dinner," we've got a subject, what did they do? They ordered, but we've got this subordinating conjunction here. So we know that when we've got a subordinating conjunction at the beginning of a clause, that makes it a dependent clause, so there is our dependent clause. And then we have "their eyes were bigger than their stomachs." The subject is "their eyes were bigger than their stomachs" that can stand on its own, so we've got an independent clause there and we have this combination again, the comma and the conjunction 'so', that are hooking up "they had lots of leftovers." Again "they" is our subject, "had" is our predicate and the thought is complete with "lots of leftovers." So we've got another independent clause. So two independent clauses hooked up to the dependent clause makes the compound complex sentence. Now I know a lot of you guys may be wondering well, why is it important that I know the sentence types. I write my sentences and that should be good enough, so I why do I have to spend time figuring out what kind of sentence they are. And what I want to take a look at is a chart that looks like this. This is what I really recommend you using in order to kind of put this knowledge to use. I would, in every paper that you write, draw up a chart here. So, I give it three columns and for each sentence, I know this might be tedious but you'll be surprised at what it reveals, for each paragraph, start plugging in your sentences. Write down the first three words of each sentence, tell me what type it is and then write down the number of words. What you'll start to see is a lot of patterns here. You might be really prone to using compound sentences all the time or you might start all your sentences with the same three words. So this chart will help you reveal what I said at the beginning that variety is the spice of writing. So you can use this and use your knowledge of sentence types in order to mix it up and make sure that you are keeping your readers on their toes as they go.