Commas in space and time | The Comma | Punctuation | Khan Academy

Hello Garans, hello Paige, hi David.

So today we're going to be talking about commas in space and time because commas have basically one function, which is separating parts of sentences. Separating parts of sentences. What's neat is that we can use commas to separate stuff out in space and separate stuff out in time. So I'm going to handle space, Paige is going to do time. It's going to be sweet.

So first of all, one way in which you can use commas to separate space is by talking about addresses—people's physical addresses in space. So the fictitious detective, private detective Nero Wolfe, one of my very favorites, is supposed to live at 454 West 35th Street in New York. So if I wanted to write Mr. Wolfe a letter—and I would write him a letter because he hates talking on the phone—I would address it like so, separating all elements of his address with commas:

So, Nero Wolfe, comma, 454 West 35th Street, comma, New York City, or just New York, comma, New York.

And then I would put the ZIP code, which I think is 1-1, but I'm not sure if they had zip codes when those stories took place. But it doesn't matter. You separate out all of these elements with commas. This isn't just for writing addresses; this is for referring to any point in space on the planet. So if I wanted to tell you the name of my favorite city on the planet, I would say, Wagadu, comma, Bina Faso—a real place I've never been there. I would like to go someday.

And that is how you use commas in space. Paige, how are commas used in time?

So commas are used in dates. Okay? So I could say, on Tuesday, comma, October 5th, comma, 2010, comma, I ate a cricket. So as you can see, we've separated the day of the week, mhm, from the day of the month, right? October 5th from the year 2010, and then separated all that from the rest of the sentence: I ate a cricket—because all of this is like a prepositional phrase that is modifying the word "ate," true.

So we want to make sure that all of it is separated out from the rest of the sentence, and we separate it out using our friend, the comma, of course. So if you want to express a kind of complicated relationship in time or in space, you want to deliver— you want to make sure a letter gets to a very specific place. You want to talk about a very specific city in a very specific country; you use commas. You want to talk about a very specific time, you use commas.

That's commas in space and time, my Grim marians. You can learn anything.

David out, Paige out.