Interval.md

@@ -12,20 +12,20 @@ create_table "courses" do |t|
 end
 ```
 
-Or when you are adding or column, just use `:interval` as type.
+Or when you are adding a column, just use `:interval` as its type.
 ```ruby
 add_column :courses, :duration, :interval
 ```
 
 ### Using it
 
-The column is automatically identified and the value is turned into `ActiveSupport::Duration`. So, any of the methods available on it can be used directly from your field. [RubyOnRails Doc](http://api.rubyonrails.org/classes/ActiveSupport/Duration.html)
+The column is automatically identified and its value turned into `ActiveSupport::Duration`. So, any methods available on it can be used directly from your field. [RubyOnRails Doc](http://api.rubyonrails.org/classes/ActiveSupport/Duration.html)
 ```ruby
 # Shows when you'll be finishing the course
 course.duration.from_now
 ```
 
-The value can be set in different manners:
+The value can be set in some different manners:
 ```ruby
 course.duration = 1.year                 # A new instance of ActiveSupport::Duration
 course.duration = [1, 2, 3, 4, 5, 6]     # A list of values for the given order Y-M-D H:M:S