diff --git a/src/arrays_ii/initialization_with_size.md b/src/arrays_ii/initialization_with_size.md
index e076ff4c..109c9f7e 100644
--- a/src/arrays_ii/initialization_with_size.md
+++ b/src/arrays_ii/initialization_with_size.md
@@ -1,11 +1,11 @@
-# Initializion with Size
+# Initialization with Size
 
 The Nintendo GameBoy had a screen resolution of 160 x 144.
 To store the value of each pixel[^bw] you would need an array 23,040 items 
 long.
 
 To support this without you writing the word `false` 23,040 times,
-arrays can be made with just by giving a size and skipping the initializer.
+arrays can be made just by giving a size and skipping the initializer.
 
 ```java,no_run
 boolean[] pixels = new boolean[23040];
@@ -14,4 +14,4 @@ boolean[] pixels = new boolean[23040];
 So you have to say `new` followed by the type of element in the array, `[`, the size of the array and `]`.
 
 
-[^bw]: The original GameBoy wasn't actually just black and white. It supported 7 shades of gray, so a `boolean` wouldn't technically to be enough to represent a pixel's state. You'd have to use something with at least 8 states, not just 2.
+[^bw]: The original GameBoy wasn't actually just black and white. It supported 7 shades of gray, so a `boolean` wouldn't technically be enough to represent a pixel's state. You'd have to use something with at least 8 states, not just 2.
diff --git a/src/classes/challenges.md b/src/classes/challenges.md
index d7bf2207..94fbdeed 100644
--- a/src/classes/challenges.md
+++ b/src/classes/challenges.md
@@ -105,7 +105,7 @@ class SquareRoot {
     double negativeRoot;
 }
 
-void squareRoot(double value) {
+SquareRoot squareRoot(double value) {
     // -----------
     // CODE HERE
     // -----------
diff --git a/src/classes/field_access.md b/src/classes/field_access.md
index 15706c6d..e7975fed 100644
--- a/src/classes/field_access.md
+++ b/src/classes/field_access.md
@@ -1,6 +1,6 @@
 # Field Access
 
-You can access the value of any field on a class by writing the name of a variable holding an instance
+You can access the value of any field in a class by writing the name of a variable holding an instance
 of that class, `.`, then the name of that field.
 
 ```java
diff --git a/src/classes/field_initialization.md b/src/classes/field_initialization.md
index 0a3461f7..43394880 100644
--- a/src/classes/field_initialization.md
+++ b/src/classes/field_initialization.md
@@ -2,7 +2,7 @@
 
 You can set an initial value for a field in a few ways.
 
-One is to access to assign the field directly on the instance created.
+One is to assign the field directly on the instance created.
 
 ```java
 class Muppet {
diff --git a/src/classes/instances.md b/src/classes/instances.md
index 2131840c..2737938c 100644
--- a/src/classes/instances.md
+++ b/src/classes/instances.md
@@ -15,7 +15,7 @@ void main() {
 }
 ```
 
-Very similarly to arrays, the output from printing an instance of a class might seem like gibberish (`Main$Muppet@1be6f5c3`).
+Very similar to arrays, the output from printing an instance of a class might seem like gibberish (`Main$Muppet@1be6f5c3`).
 You will learn how to make it nicer later.
 
 [^var]: I haven't used it in many code samples thus far, but if you remember `var` this is one of the times
diff --git a/src/instance_methods.md b/src/instance_methods.md
index e499cb06..2cc4255c 100644
--- a/src/instance_methods.md
+++ b/src/instance_methods.md
@@ -19,5 +19,5 @@ class Muppet {
 We call these instance methods because you need an instance of the class in order
 to call the method.
 
-[^kermitangry]: If you haven't seen the muppets this might have go over your head,
+[^kermitangry]: If you haven't seen the muppets this might go over your head,
 but Kermit [randomly gets really mad.](https://www.youtube.com/watch?v=SVDgHEg2jnY)
\ No newline at end of file