diff --git a/relational-data.Rmd b/relational-data.Rmd
index 39734e1..6010c32 100644
--- a/relational-data.Rmd
+++ b/relational-data.Rmd
@@ -58,7 +58,7 @@ One way to show the relationships between the different tables is with a drawing
 knitr::include_graphics("diagrams/relational-nycflights.png")
 ```
 
-This diagram is a little overwhelming, and even so it's simple compared to some you'll see in the wild! The key to understanding diagrams like this is to remember each relation always concerns a pair of tables. You don't need to understand the whole thing; you just need the understand the chain of relations between the tables that you are interested in.
+This diagram is a little overwhelming, and even so it's simple compared to some you'll see in the wild! The key to understanding diagrams like this is to remember each relation always concerns a pair of tables. You don't need to understand the whole thing; you just need to understand the chain of relations between the tables that you are interested in.
 
 For nycflights13: