fix: typo spelling grammar

docs/types/never.md

@@ -74,15 +74,15 @@ const failExpression = function(message: string) {
 };
 ```
 
-Of course you can fix it by an explict annotation: 
+Of course you can fix it by an explicit annotation: 
 
 ```ts
 function failDeclaration(message: string): never {
   throw new Error(message);
 }
 ```
 
-Key reason is backword compatability with real world JavaScript code: 
+Key reason is backword compatibility with real world JavaScript code: 
 
 ```ts
 class Base {
@@ -100,7 +100,7 @@ class Derived extends Base {
 
 If `Base.overrideMe` . 
 
-> Real world TypeScript can overcome this with `abstract` functions but this inferrence is maintained for compatability.
+> Real world TypeScript can overcome this with `abstract` functions but this inferrence is maintained for compatibility.
 
 <!--
 PR: https://github.com/Microsoft/TypeScript/pull/8652

docs/types/type-compatibility.md

@@ -207,7 +207,7 @@ status = num; // OKAY
 num = status; // OKAY
 ```
 
-* Enum values from different enum types are considered incompatible. This makes enums useable *nominally* (as opposed to structurally)
+* Enum values from different enum types are considered incompatible. This makes enums usable *nominally* (as opposed to structurally)
 
 ```ts
 enum Status { Ready, Waiting };