If you have a sentence with two complete thoughts, but you don't punctuate it properly, it can become what we call a run-on sentence. So all sentences include at least one complete thought, but if you have two complete thoughts, it can get a little bit tricky. I'm going to show you four ways to punctuate a sentence with two complete thoughts in a way that avoids a run-on. So say that I want to express this idea. I love grammar. How about you? Well the first way that I can punctuate this is with a period, and to essentially create two sentences.
So I'm breaking these two complete thoughts into two sentences. I love grammar. How about you? Another way to do it is what I call the comma conjunction. And so we can join these two ideas with a comma and a conjunction. For example, "I love grammar, and how about you?" The third way that we can punctuate this type of sentence properly is with a semicolon. And in this case we would say, "I love grammar; how about you?" And it's always important to remember that when you use a semicolon, you lower-case the word that comes after it. This is all still one sentence. And the fourth way, and I think the trickiest but kind of the neatest way, to join these two ideas correctly is to use a semicolon and a word like however.
So in this case it gives us a sentence that says, "I love grammar; however, do you?" And however is a little bit different than a typical conjunction. It's what we call a conjunctive adverb, and because of it, it gets this special treatment when it's linking two ideas. We can't just do comma however. We need to have a semicolon, however, comma. I kind of call it the semicolon-comma cushion that these special words like however or therefore need. So again, these are the four ways to properly punctuate a sentence with more than one idea to avoid a run-on sentence.