Commas and introductory elements

- [Voiceover] Hello grammarians! Paige and I are here to teach you about introductory elements in sentences and how commas relate to them. Paige, how should we define what an introductory element is? - [Voiceover] So, it's pretty much something that happens at the beginning of a sentence. It can be a dependent clause or an adverb. But as we will see soon, it is something that is separated off with, of course, a comma. - [Voiceover] Because that's what commas do. They are separators. So, let's talk about dependent clauses first. And let me just write out a sentence that begins with a dependent clause. "When you come in, please take off your shoes." And I've made the difference between the dependent clause and the independent clause pretty clear. So, this the dependent clause is purple, the independent clause is green. Is there a need for a comma here? - [Voiceover] Of course. - [Voiceover] Okay. (Paige laughs) Because we're leading with a dependent clause, and that means that this thing can't stand on it's own, right? It's like the ladder up against the tree. Because an independent clause, in green, can stand on its own; a dependent clause cannot. So, we need to differentiate it from the rest of the sentence by putting the comma there. So, this is a dependent clause. And this is an independent clause. So, if you start a sentence with a dependent clause, you're gonna need to put the comma in the middle before you proceed to the independent clause, which is the part that makes it an actual functioning sentence. - [Voiceover] Right. - [Voiceover] If you have it the other way around though, if it's just, "Please take off your shoes when you come in," no need for a comma. I'll show you. So, I'm not sure why this is. I think it may just sort of be a style relic. I'm not entirely certain. I mean, if you go back in American history and you look at the Federalist Papers and you look at the way that people used commas in the 18th century, it doesn't make a whole lot of sense, relative to how we use commas today. So, a lot of this is cultural. But I can tell you that when an independent clause comes before a dependent clause, you don't use a comma. And if you are uniting two independent clauses, in the following sentence, "I rode an elephant "and then I ate a mango," these two things are both independent clauses, right? I rode an elephant. Then I ate a mango, right? These two things need to be connected by this conjunction, and. But that's not all. They also need to be joined by a comma. Now, you could also sub out, if you wanted to, get rid of this comma and this and and put in a semicolon, but that's a story for another time. So, if you're uniting two independent clauses, just do comma and then a conjunction. So, that's one way to think about how to use commas for introductory elements like dependent and independent clauses. But there's also another thing I wanna introduce you to, and that's sentence adverbs. Follow us over to the next screen. So, Paige, what is a sentence adverb? How does it work? - [Voiceover] So, we've been talking about starting sentences with clauses, but that doesn't always have to be the case. You can start a sentence with an adverb. Like, let's say, "Initially, I was afraid." - [Voiceover] So, what is initially doing in this sentence here, in this expression? - [Voiceover] Basically, it's modifying the whole rest of the sentence. It's modifying the "I was afraid." - [Voiceover] So, we're gonna put a comma here to separate it from the rest of that expression. That's why we call it a sentence adverb, 'cause it's not, this is not the same as saying, "I was initially afraid." This is kind of, like you said, modifying the entire expression. Let's look at another example. - [Voiceover] "Basically, you're the greatest." - [Voiceover] Aww, thanks, Paige! So, we've got this word, basically, and basically is modifying the entire expression. It's kind of qualifying the whole thing. - [Voiceover] Right. - [Voiceover] So, we're gonna put a comma between this sentence adverb and the sentence itself. - [Voiceover] Exactly. - [Voiceover] Cool, so, initially, Paige, this seemed pretty complicated to me. - [Voiceover] Right, but, basically, I think we got it down. - [Voiceover] All right, we think that, essentially, you can learn anything. - [Voiceover] David out. - [Voiceover] Paige out.