When you started learning English, this is one of the first words you learned, e.g. "This is a book." Right? It indicates something close to the speaker. But what if I told you it had another important usage that they don't really teach you, but that we use constantly in the spoken language? 

I like to call it the third article. We all know about the indefinite article a(n), and the definite article the, and how they work; when you mention something for the first time, you call it a, and after that, you can call it the because both you and the listener are now familiar with it. In other words, first something is indefinite and then it's definite. 

For example, this in this snippet from 003 Mahinarangi:

I recently came across this article online about a woman in New Zealand who has a little girl named Mahinarangi (and I know I’m saying it correctly because I actually googled the pronunciation). At any rate, the article was about the fact that the woman was livid because the people at her daughter’s daycare had “shortened her name without her permission” because it was too hard to pronounce.

However, here we'll see that instead of a(n), we can also use this (plural these) when we're telling a story and introducing someone or something for the first time. In this usage, the subject is kind of definite because the speaker's familiar with them, but it's also kind of indefinite because the listener isn't, so it's sort of a one-sided definiteness. For instance, in 001 Nacho & Flor and again in 002 Birdwatching, I use this to introduce Samantha and Roman:

Here we see that although this is normally used to refer to something definite or specific, we can use it in a narrative to mention someone or something for the first time, but with a bit of a twist: using this in this way, tells the listener «pay attention to this person/thing — they play a role in this story». In other words, this is how we "mark" the players in our story, whether they be people or things.

Note that just like the articles a(n) and the, this and plural these are always totally unstressed in this usage.

In the spoken language, when telling a story or recounting any kind of narrative, we use this to mark a person or thing that's going to figure in the story. For instance, in this snippet, this woman starts out as a total stranger, but as the story develops, she becomes more and more significant to the storyline and the speaker.

The strangest thing happened this morning. I was in Starbucks, and this woman walks up to me and asks me if I'd buy her a coffee. Of course, I said yes. She looked homeless. So she orders herself a coffee and I pay for it. While we're waiting for our orders, we have a little chat. The more she talked, the more familiar she sounded. I couldn't place the face, but her voice was really familiar. Then she mentions that she'd been a teacher, and I realize it's Miss Taylor, my third grade teacher, who's obviously fallen on hard times. So sad.

Some speakers use this/these extensively to mark all the elements and characters in their story. You really can't overuse it because again, in the narrative style, it sounds very natural. If you look at the phrases in blue in the example below, you'll see all the elements that the speaker considered part to the story.

Note that when you wish to highlight one element of several, you can use this in combination with stressed óne, as in this óne morning and this óne tattoo in the snippet below. This usage is also heard with time elements. You'll hear people start stories with phrases like this óne time, this óne summer, this óne day, etc. In this story, for instance, this óne morning is the same as saying one morning, but marking it as a particular morning where something notable happened in their story, and not just some random morning out of many.


This isn't the same this one as you hear in I want thís one, where the word this is stressed; In this usage, this is totally unstressed and one is stressed: this óne tattóo.
Here, this óne morning doesn't mean the same as this morning meaning today. It's one particular morning of many. Similarly, this óne tattoo points to one specific tattoo of the many the woman had. Here, the speaker is marking every significant element of the story with this/these. This may sound excessive to you, but to the American ear, it just sounds like, well... a story.

This one morning on the way to work, I stopped into this new café that had just opened to get some coffee. There was this girl standing in line in front of me with all these tattoos all over her. This one tattoo on her neck had this strange writing, which I thought was Chinese, but when I took a closer look, I realized it was in English: "If you can read this, you're too close!"