A version of this post originally appeared on The Week.

Sheena McFeely is a deaf mom with a YouTube channel* where she and her husband Manny Johnson teach signs with the help of their two adorable daughters, one deaf, one hearing, both native, fluent users of American Sign Language. Last month, she posted this wonderful video of Shaylee, who is deaf, signing a version of “‘Twas the Night Before Christmas.”

You don’t have to know anything about sign language to be blown away by the sheer force of personality coming through in Shaylee’s performance. But with a little knowledge of how ASL works, you can also be amazed by the complexity of her linguistic and storytelling skills. Here are nine great moments from Shaylee’s video.

1. At 0:30, she signs a complex sentence with a topic-comment structure. She introduces a long noun phrase (“a mouse that was running about”), and says something about it (“is now still”). The topic noun phrase is indicated by her eyebrow raise. She lowers her eyebrows appropriately for the comment part. A big sentence for a little girl.

2. Here, she uses a discourse strategy called role shift to great effect. She introduces the stockings as straight narration, with her eye gaze straight ahead, but then, describing how the stockings looked, she shifts her gaze toward the point in space where she has established their location, allowing her to use her facial expression to express a reaction to their beauty. And what an expression!

3. Again, she uses role shift, this time to provide coherence for a series of clauses. She introduces the children in straight narration, and then, with her face, adopts the role of the sleeping children, while maintaining the narration with her signs. The role adoption lasts as long as she produces clauses which have “the children” as their subject. Then she effortlessly shifts back out of the role. Anyone who has tried to learn ASL as a second language can tell you this is not easy to do.

4. This role shift, where her slightly worried expression represents dad’s reaction, also provides coherence. She adopts the dad role with her face as he springs from bed, then shifts to neutral narration to explain that it was because of a noise, then shifts back to dad as the action continues.

5. She makes the sign for “old” in an exaggerated, extra long way. It’s like she saying “old” with a slow, creaky, old person’s voice. Great, engaged storytelling.

6. In this performance, she’s not only representing a neutral narrator and a bunch of roles within the story, she’s also herself with her own opinions. Here, for a moment, her own feelings about Santa shine through, without breaking the rhythm of the story.

7. She continues to shift perspectives smoothly from dad to narrator to Santa and back without missing a beat.

8. This is a great illustration of how what she is doing with her role shifting is very different from simple playacting or pantomime. Her head turns to show Santa’s head turning, and she winks to show Santa winking, but at the same time she produces the correct ASL signs for head movement (the flat “base” hand, the fist, the orientation change from palm into to palm out) and the ASL sign for wink (an actual wink is not an ASL sign). She is acting and performing and expressing emotions and moods, but all within a linguistic context—just as you would be doing with your voice and face if you were telling this story (assuming you were any good at it, that is).

9. “Merry Christmas to all and to all a good night.” As she slows down to deliver the last line, she holds your attention in the palms of her capable little hands. Can you hear, and see, Santa’s voice echoing over the quiet, snowy landscape? Was there ever a sweeter end to this poem?

*To turn on the English captions for the videos, click the CC button at the bottom of the YouTube screen.

More from The Week:

11 wonderful winter weather terms

‘Tis and 10 other fun proclitic words

’You and I’ vs. ‘You and me’