diff --git a/assets/files/robots.txt b/assets/files/robots.txt
new file mode 100644
index 0000000..7930672
--- /dev/null
+++ b/assets/files/robots.txt
@@ -0,0 +1,3 @@
+User-agent: *
+Disallow:
+Sitemap: https://phpapprentice.com/sitemap.xml
diff --git a/assets/files/sitemap.xml b/assets/files/sitemap.xml
new file mode 100644
index 0000000..d9fb94d
--- /dev/null
+++ b/assets/files/sitemap.xml
@@ -0,0 +1,117 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset
+      xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
+      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+      xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9
+            http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
+<!-- created with Free Online Sitemap Generator www.xml-sitemaps.com -->
+
+
+<url>
+  <loc>https://phpapprentice.com/</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>1.00</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/installing-php.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/basics.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/variables.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/arithmetic.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/strings.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/comparisons.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/boolean-logic.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/conditionals.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/loops.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/arrays.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/functions.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/classes.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/classes-inheritance.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/classes-visibility.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/classes-constructor.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/static.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/interfaces.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/abstract.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/exceptions.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+<url>
+  <loc>https://phpapprentice.com/credits.html</loc>
+  <lastmod>2018-12-27T01:20:29+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
+
+
+</urlset>
diff --git a/assets/templates/index.phtml b/assets/templates/index.phtml
index 0fa74e5..acb6352 100644
--- a/assets/templates/index.phtml
+++ b/assets/templates/index.phtml
@@ -15,7 +15,7 @@
                 The site currently has content for learning the basics of PHP. In the future, more pages will be added for more advanced topics like building websites, database integration and security.
             </p>
             <p>
-                PHP Apprentice is currently a work in progress. If you would like to contribute or request a certain discussion topic, checkout the <a href="https://github.com/restoreddev/phpapprentice" target="_blank">GitHub repository</a>.
+                PHP Apprentice is currently a work in progress. If you would like to contribute or request a certain discussion topic, check out the <a href="https://github.com/restoreddev/phpapprentice" target="_blank">GitHub repository</a>.
             </p>
             <p>
                 To get started, you will need to <a href="<?php echo page_path('installing-php') ?>">install</a> PHP, have a text editor and open your terminal.
diff --git a/code/arrays.php b/code/arrays.php
index c80b82f..0891bc1 100644
--- a/code/arrays.php
+++ b/code/arrays.php
@@ -1,6 +1,8 @@
 <?php
 
+// In PHP, arrays are used to store a list of items in a single variable.
 // There are two ways to create an array.
+
 // First, you can use the array construct to pass in values separated by commas
 // and it will return an array.
 $taskList = array('grocery store', 'change car oil');
diff --git a/code/classes-constructor.php b/code/classes-constructor.php
index 34adcc5..b597e05 100644
--- a/code/classes-constructor.php
+++ b/code/classes-constructor.php
@@ -19,7 +19,7 @@ class Ballcap
 {
     public $color;
 
-    public function __construct($color )
+    public function __construct($color)
     {
         $this->color = $color;
     }
diff --git a/code/exceptions.php b/code/exceptions.php
index 6548bfe..d813866 100644
--- a/code/exceptions.php
+++ b/code/exceptions.php
@@ -20,7 +20,7 @@ $processor = new Processor();
 $processor->charge('1234');
 
 // A developer who wants to prevent an exception from stopping code execution
-// can catch the exception and use it for logging or a return an error to a user.
+// can catch the exception and use it for logging or display the error to a user.
 
 // Just wrap the code that might throw an exception with the keyword "try" and brackets
 // followed by "catch", the exception type in parentheses and more brackets.