Fixed typos

exercises/concept/wizards-and-warriors/.docs/hints.md

@@ -9,7 +9,7 @@ The whole inheritance concept has a lot to do with the concepts around [overridi
 
 - In Java, the `toString()` method is actually present inside the `Object` class (which is a superclass to all the classes in Java).
   You can read more about it [here][object-class-java].
-- To override this method inside your implementation class, you should have a method with same name i.e `toString()` and same return type i.e `String`.
+- To override this method inside your implementation class, you should have a method with same name i.e. `toString()` and same return type i.e. `String`.
 
 ## 2. Making Fighters not vulnerable by default
 

exercises/concept/wizards-and-warriors/.docs/introduction.md

@@ -2,9 +2,8 @@
 
 ## Inheritance
 
-Inheritance is a core concept in OOP (Object Oriented Programming). It donates IS-A relationship.
-It literally means in programming as it means in english, inheriting features from parent(in programming features is normally functions
-and variables).
+Inheritance is a core concept in OOP (Object-Oriented Programming). It donates IS-A relationship.
+It literally means in programming as it means in english, inheriting features from parent(in programming features is normally functions and variables).
 
 Consider a class, `Animal` as shown,
 
@@ -13,7 +12,7 @@ Consider a class, `Animal` as shown,
 public class Animal {
 
     public void bark() {
-        System.out.println("This is a animal");
+        System.out.println("This is an animal");
     }
 
 }

exercises/concept/wizards-and-warriors/.meta/src/reference/java/Fighter.java

@@ -3,7 +3,7 @@ abstract class Fighter {
     /**
      * this method sets the default vulnerability to false for all the child classes.
      *
-     * @return the vulnerability i.e false.
+     * @return the vulnerability i.e. false.
      */
     boolean isVulnerable() {
         return false;