diff --git a/book/src/ch2/index.md b/book/src/ch2/index.md
index c92c8dc..1263ced 100644
--- a/book/src/ch2/index.md
+++ b/book/src/ch2/index.md
@@ -12,7 +12,7 @@ modern computer or console you do this with vsync info from the GPU and Monitor,
 and on the GBA we'll be using vsync info from an IO register that tracks what
 the display hardware is doing.
 
-As a way to apply our knowledge We'll make a simply "light cycle" game where
+As a way to apply our knowledge We'll make a simple "light cycle" game where
 your dot leaves a trail behind them and you die if you go off the screen or if
 you touch your own trail. We just make a copy of `hello2.rs` named
 `light_cycle.rs` and then fill it in as we go through the chapter. Normally you