diff --git a/exercises/Making-choices-size-estimates-by-name-R.md b/exercises/Making-choices-size-estimates-by-name-R.md
index e3370a1d..6fb39457 100644
--- a/exercises/Making-choices-size-estimates-by-name-R.md
+++ b/exercises/Making-choices-size-estimates-by-name-R.md
@@ -5,7 +5,7 @@ title: Size Estimates by Name
 language: R
 ---
 
-Youre going to write a function to estimate a dinosaur's mass based on its length.
+You're going to write a function to estimate a dinosaur's mass based on its length.
 The general form of the equation for doing this is:
 
 > mass <- a * length ^ b