diff --git a/actionpack/lib/action_controller/metal/live.rb b/actionpack/lib/action_controller/metal/live.rb
index 0dd788645b..b7d1334dd3 100644
--- a/actionpack/lib/action_controller/metal/live.rb
+++ b/actionpack/lib/action_controller/metal/live.rb
@@ -48,7 +48,7 @@ module Live
     #   the server will receive a +Last-Event-ID+ header with value equal to +id+.
     #
     # After setting an option in the constructor of the SSE object, all future
-    # SSEs sent accross the stream will use those options unless overridden.
+    # SSEs sent across the stream will use those options unless overridden.
     #
     # Example Usage:
     #
diff --git a/actionpack/lib/action_dispatch/journey/parser.rb b/actionpack/lib/action_dispatch/journey/parser.rb
index bb4cbb00e2..430812fafe 100644
--- a/actionpack/lib/action_dispatch/journey/parser.rb
+++ b/actionpack/lib/action_dispatch/journey/parser.rb
@@ -1,7 +1,7 @@
 #
 # DO NOT MODIFY!!!!
 # This file is automatically generated by Racc 1.4.9
-# from Racc grammer file "".
+# from Racc grammar file "".
 #
 
 require 'racc/parser.rb'
diff --git a/actionpack/lib/action_dispatch/middleware/templates/routes/_table.html.erb b/actionpack/lib/action_dispatch/middleware/templates/routes/_table.html.erb
index 95461fa693..323873ba4b 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/routes/_table.html.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/routes/_table.html.erb
@@ -89,8 +89,8 @@
   }
 
   // takes an array of elements with a data-regexp attribute and
-  // passes their their parent <tr> into the callback function
-  // if the regexp matchs a given path
+  // passes their parent <tr> into the callback function
+  // if the regexp matches a given path
   function eachElemsForPath(elems, path, func) {
     each(elems, function(e){
       var reg = e.getAttribute("data-regexp");
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index b8abdabca5..04faabef37 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -361,7 +361,7 @@ module MountedHelpers #:nodoc:
         include UrlFor
       end
 
-      # Contains all the mounted helpers accross different
+      # Contains all the mounted helpers across different
       # engines and the `main_app` helper for the application.
       # You can include this in your classes if you want to
       # access routes for other engines.
diff --git a/activemodel/lib/active_model/conversion.rb b/activemodel/lib/active_model/conversion.rb
index 21e4eb3c86..1856c852a2 100644
--- a/activemodel/lib/active_model/conversion.rb
+++ b/activemodel/lib/active_model/conversion.rb
@@ -41,7 +41,7 @@ def to_model
     end
 
     # Returns an Enumerable of all key attributes if any is set, regardless if
-    # the object is persisted or not. If there no key attributes, returns +nil+.
+    # the object is persisted or not. Returns +nil+ if there are no key attributes.
     #
     #   class Person < ActiveRecord::Base
     #   end
diff --git a/activerecord/lib/active_record/counter_cache.rb b/activerecord/lib/active_record/counter_cache.rb
index 7e3bef9431..dcbdf75627 100644
--- a/activerecord/lib/active_record/counter_cache.rb
+++ b/activerecord/lib/active_record/counter_cache.rb
@@ -82,10 +82,10 @@ def update_counters(id, counters)
 
       # Increment a numeric field by one, via a direct SQL update.
       #
-      # This method is used primarily for maintaining counter_cache columns used to
-      # store aggregate values. For example, a DiscussionBoard may cache posts_count
-      # and comments_count to avoid running an SQL query to calculate the number of
-      # posts and comments there are each time it is displayed.
+      # This method is used primarily for maintaining counter_cache columns that are
+      # used to store aggregate values. For example, a DiscussionBoard may cache
+      # posts_count and comments_count to avoid running an SQL query to calculate the
+      # number of posts and comments there are, each time it is displayed.
       #
       # ==== Parameters
       #
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index 7e38719811..2602f79db9 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -188,7 +188,7 @@ def initialize(errors)
     end
   end
 
-  # Raised when a primary key is needed, but there is not one specified in the schema or model.
+  # Raised when a primary key is needed, but not specified in the schema or model.
   class UnknownPrimaryKey < ActiveRecordError
     attr_reader :model
 
diff --git a/guides/source/credits.html.erb b/guides/source/credits.html.erb
index 5beae9c29b..7c6858fa2c 100644
--- a/guides/source/credits.html.erb
+++ b/guides/source/credits.html.erb
@@ -76,5 +76,5 @@ Oscar Del Ben is a software engineer at <a href="http://www.wildfireapp.com/">Wi
 <% end %>
 
 <%= author('Akshay Surve', 'startupjockey', 'akshaysurve.jpg') do %>
-  Akshay Surve is the Founder at <a href="http://www.deltax.com">DeltaX</a>, hackathon specialist, a midnight code junkie and ocassionally writes prose. You can connect with him on <a href="https://twitter.com/akshaysurve">Twitter</a>, <a href="http://www.linkedin.com/in/akshaysurve">Linkedin</a>, <a href="http://www.akshaysurve.com/">Personal Blog</a> or <a href="http://www.quora.com/Akshay-Surve">Quora</a>.
+  Akshay Surve is the Founder at <a href="http://www.deltax.com">DeltaX</a>, hackathon specialist, a midnight code junkie and occasionally writes prose. You can connect with him on <a href="https://twitter.com/akshaysurve">Twitter</a>, <a href="http://www.linkedin.com/in/akshaysurve">Linkedin</a>, <a href="http://www.akshaysurve.com/">Personal Blog</a> or <a href="http://www.quora.com/Akshay-Surve">Quora</a>.
 <% end %>