More Uses of Commas Video Lecture

In this lesson you’ll learn more about using commas. You’ve already learned about compound sentences and how we join two independent clauses with a comma and a conjunction, like and or but. You’ve also learned about compound sentences where we joined the two independent clauses with a transition word like therefore, and we use a semicolon and a comma to punctuate those. You’ve also learned to use commas in a series or a list of things. Remember when you have a series of three or more items, that means three nouns, verbs, or adjectives, you need to put commas between them. Now we’re going to learn about using commas with introductory phrases. An introductory phrase is a group of words that starts your sentence, but does not belong to the main clause of the sentence. You can usually find an introductory phrase because it comes before the subject of the sentence. Look at the first sentence. Due to the bad weather, our game was canceled. Due to the bad weather is an introductory phrase. We can take this off and we still have the sentence, our game was canceled. That’s your main clause, so the introductory phrase comes before the main clause, and you put a comma to separate them. In the next sentence, on Monday, my teacher announced a test. On Monday is the introductory phrase, so we put a comma after it. In the next, one after dinner, Steve watched the news. After dinner is the introductory phrase, it goes before the main clause of the sentence, so we put a comma after it. In the next one, because of traffic, is the introductory phrase, and then the last one, for several months, is the introductory phrase. We also need to use commas with interrupting phases. Interrupting phrases interrupt your sentence. You’ll usually find them between the subject and the verb, but they can go anywhere in the sentence. Look at the first one. The mayor, by the way, will be at the meeting. By the way is interrupting our main clause, so we need to separate it with commas. If the interrupting phrase is in the middle of the sentence, you’ll need two commas. Look at the next one. This is the reason, therefore, that you should buy a house. Therefore is our interrupting phrase. We could take this word out and our sentence would be fine without it. So therefore is interrupting the sentence and we have to put commas around it. In the last one Joe wants to buy a house too. Too is our interrupting phrase. Now, it’s actually at the end of the sentence, but it’s extra information, and we have to separate it with a comma. If your interrupting phrase comes at the end of the sentence, you’ll only use one comma. Here are some other interrupting elements. These are adjective clauses. Look at the first sentence. My roommate, who hates seafood, doesn’t want me to cook shrimp. Who hates seafood, is extra information in this sentence, and it’s interrupting the main sentence. I could take this out, but I want to use it for extra information. When I do that, I have to put commas around it. So there’s a comma in front and a comma after the interrupting element. Look at the second example. The dress, which I bought for tonight, is too tight for me to wear. Again this interrupting element is extra information, I’m describing something about the dress, but because it’s extra information, and it’s interrupting the rest of the sentence, I have to separate it with commas. Try this exercise for practice. Decide if the sentence needs commas or not. Pause your video and write your answers on some paper. Pause the video now. Now check your answers. The words in red are introductory phrases and interrupting words. Make sure that you put commas in the correct places. Let’s review. Remember that you need commas in compound sentences that have conjunctions. You put a comma before conjunctions like and, but and or. You also use commas in a series when you have three or more nouns, verbs or adjectives. We also saw that you use commas after an introductory phrase. Introductory phrases start your sentence, and they come before the subject of the sentence. Put a comma after these phrases. We also put commas around any interrupting phrases and clauses. When a phrase interrupts the rest of your sentence, you separate it by commas.