Fix some typos

Author: nikic

Book/php7/introduction.rst

@@ -10,13 +10,13 @@ There are three primary goals of this book:
  * Document and describe how to extend the language with extensions.
  * Document and describe how you can interact with the community to develop PHP itself.
 
-This book is primarily targeted at developers who have experience in the C programming language. However, where-ever
+This book is primarily targeted at developers who have experience in the C programming language. However, wherever
 possible we will attempt to distill the information and summarize it so that developers who don't know C well, will
 still be able to understand the content.
 
 However, let us insist. You won't be able to achieve something productive, stable (crash free under any platform), 
 performant and useful, if you don't know the C language. Here are some pretty nice online resources about the C 
-language itself, its ecosystem and build tools, and Operating System APIs :
+language itself, its ecosystem and build tools, and Operating System APIs:
 
 * http://www.tenouk.com/
 * https://en.wikibooks.org/wiki/C_Programming
@@ -25,7 +25,7 @@ language itself, its ecosystem and build tools, and Operating System APIs :
 * http://www.faqs.org/docs/Linux-HOWTO/Program-Library-HOWTO.html
 * http://www.iecc.com/linker/linker10.html
 
-We also highly recommand you some books. You'll learn with them how to efficiently use the C language, and how to 
+We also highly recommend you some books. You'll learn with them how to efficiently use the C language, and how to
 make it translate to efficient CPU instructions so that you can design strong/fast/reliable and secure programs.
 
 * The C Programming Language (Ritchie & Kernighan)