diff --git a/0-introduction.md b/0-introduction.md
index 67e428b..f6e9584 100644
--- a/0-introduction.md
+++ b/0-introduction.md
@@ -213,7 +213,7 @@ var visitor = {
 };
 ```
 
-However, there also exists the possibilty of calling things on "exit". Imagine
+However, there also exists the possibility of calling things on "exit". Imagine
 our tree structure from before in list form:
 
 - Program