diff --git a/types & grammar/ch1.md b/types & grammar/ch1.md
index 1f628bc3e..e2b0f3134 100644
--- a/types & grammar/ch1.md	
+++ b/types & grammar/ch1.md	
@@ -290,7 +290,7 @@ JavaScript has seven built-in *types*: `null`, `undefined`,  `boolean`, `number`
 
 Variables don't have types, but the values in them do. These types define intrinsic behavior of the values.
 
-Many developers will assume "undefined" and "undeclared" are roughly the same thing, but in JavaScript, they've quite different. `undefined` is a value that a declared variable can hold. "Undeclared" means a variable has never been declared.
+Many developers will assume "undefined" and "undeclared" are roughly the same thing, but in JavaScript, they're quite different. `undefined` is a value that a declared variable can hold. "Undeclared" means a variable has never been declared.
 
 JavaScript unfortunately kind of conflates these two terms, not only in its error messages ("ReferenceError: a is not defined") but also in the return values of `typeof`, which is `"undefined"` for both cases.