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Unit 11: Lesson 3

Writing: Grammar

Writing: Commas — Video Lesson

David shows you how to think through a commas question on the SAT Writing and Language test. Created by David Rheinstrom.

Video transcript

- [Instructor] Let's take a look at question 28 here. This is an excerpt from a passage about Bird in Space, an abstract sculpture. 'Works of art could be imported 'to the United States duty-free, 'but industrial materials were taxed at rates 'of up to 40% of their purchase value.' Okay, so we've got choice A, which is no change, and that means that there is a comma between art and could. I'm gonna circle that comma. Choice B has a dash between art and could. Choice C has no punctuation between art and could. And choice D has a comma after could so between could and be imported. So this is a punctuation question. There are five to six questions about punctuation on your official SAT, and comma questions are the most common of those. I see two kinds of punctuation used in these choices: dashes and commas. Let's talk very quickly about how those two pieces of punctuation work. Okay, so first of all, this is a dash. A dash is long. What a dash is not, is not the short version, which is called the hyphen. That's the short little punctuation mark you might see in a word like merry-go-round. The SAT does not test the use of hyphens. So dashes can be used in pairs, like commas can, to set off asides and nonessential elements like 'The cello, a stringed instrument, 'has a warm sound.' Right, so here we've got a pair. Here's dash one, here's dash two. It sets off this aside. A single dash, however, behaves like a colon. It has to follow an independent clause. It has to come after something that would work on its own as a full sentence. 'Here's the thing - I've never met her in my life!' Here's the thing is an independent clause. Here is the thing. That's a sentence that could stand on its own. Where is the thing? Here is the thing, the thing is here. It's an independent clause. So that's dashes and what dashes can do. Let's turn to commas. So commas have a lot of functions. They can separate list items as in 'We need eggs, cheese, and bread.' They can set off nonessential elements as in 'Luisa, who was a werewolf, 'hated Mondays.' The core of the sentence here is 'Luisa hated Mondays'. Luisa is the subject and hated as the main verb, right? 'Who was a werewolf' describes Luisa, but it's not essential to this being a complete sentence. Commas can also link dependent clauses to independent clauses as in 'Although her workshop was tiny, 'she used it to craft wonders.' And in this case 'although her workshop was tiny' is a dependent clause. It can't stand on its own as a sentence. And 'she used it to craft wonders' is an independent clause. It can stand on its own as a sentence. And finally, commas can link two independent clauses with the help of the seven FANBOYS conjunctions: for, and, nor, but, or, yet, and so. As in 'Dogs are cuddly, but cats are noble.' Now, when it comes to punctuation questions we have a few comma top tips. My first top tip is don't split subjects and verbs. Unless you're using it to set off a nonessential phrase, a punctuation mark shouldn't come between a subject and its verb. So 'Mountain goats comma are nimble' is no good, but 'Mountain goats comma 'which have warm and soft fur comma 'are nimble' is good. Right? You can see that I'm using these paired commas to set off that nonessential element about mountain goats having warm and soft fur. The next top tip is avoid commas before prepositions. And I can see some of you raising your hands. Can you please remind us what prepositions are, David? Of course. Prepositions are words that indicate location, direction or intention like in, on, of, or to. Here's an example. 'I went comma to the grocery store' is incorrect. But if we knock out the comma, 'I went to the grocery store' is just fine. My final top tip is to look out for comma splice errors. A comma splice happens when two independent clauses link up with just a comma and no FANBOYS conjunction. 'I have many friends comma 'I love them all!' This is no good. We need to put in a word like 'and' or 'but' in there after the comma, in order for this to be a grammatically correct sentence. So that's what those commas can do. Let's head back to the question. And I'll give you this opportunity to pause the video to take your own shot at it. Now let's try it together. Okay, so choice A puts a comma between art and could. Is this part of a nonessential aside? Is 'could be imported 'to the United States duty-free' an aside? It looks like no. This is just a comma interrupting a subject and a verb. And that's one of our top tips remember. So we can knock this one out. Choice B uses a single dash. So that means it has to follow an independent clause. Does it? No, it comes right after 'works of art' and that can't be its own sentence. It doesn't have a main verb. And it's wrong for another reason, which is that it puts an unnecessary punctuation mark between a subject and a verb. So bye-bye choice B. Choice C has no punctuation in it, which is maybe to our benefit because I don't think a comma belongs here. It can't go before art or really after it because that does the top tip thing to avoid of coming between a subject and its verb. It also sounds good in context. Works of art could be imported to the US, right? I don't need a pause there. In fact, I think having a pause there would sound pretty strange. So let's look at, I think this is our answer. Let's look at D and see if we can cross it out. Okay, and choice D, yeah, puts a comma after could, which unnecessarily cuts the verb phrase 'could be imported' into two chunks. And that's reason enough for me to say that it unnecessarily separates the subject from the full verb. And like I just said, it also sounds awkward to add a pause here. Works of art could be imported. That just interrupts the flow of the idea. So I am going to knock D out, circle C, and move on. C is our answer. Our strategy for this question requires a lot of wind up. You will have to practice and be familiar with the various functions of punctuation marks like commas, colons semi-colons and dashes, but keep these things in mind. First. don't separate subjects and verbs. Unless you're using paired punctuation to set off a descriptive aside, don't include punctuation that separates subjects and verbs. Second, look for independent clauses. Semi-colons, colons, and single dashes need to follow independent clauses. If they don't, eliminate that choice. And third, related to that, avoid comma splice errors. If you see two independent clauses united by only a comma, that's no good. That choice can be eliminated. And finally, fourth, be careful around prepositional phrases. There are very few good reasons to separate a preposition from the other words it's connected to. Got more questions about punctuation? Be sure to check out our articles and our other videos. Good luck out there. You've got this!