Fix typos in Association Basics guide

guides/source/en/association_basics.md

@@ -637,7 +637,7 @@ The `create_association` method returns a new object of the associated type. Thi
 
 #### Options for `belongs_to`
 
-While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `belongs_to` association reference. Such customizations can easily be accomplished by passing options and scope blocks when you create the association. For example, this assocation uses two such options:
+While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `belongs_to` association reference. Such customizations can easily be accomplished by passing options and scope blocks when you create the association. For example, this association uses two such options:
 
 ```ruby
 class Order < ActiveRecord::Base
@@ -932,7 +932,7 @@ The `create_association` method returns a new object of the associated type. Thi
 
 #### Options for `has_one`
 
-While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `has_one` association reference. Such customizations can easily be accomplished by passing options when you create the association. For example, this assocation uses two such options:
+While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `has_one` association reference. Such customizations can easily be accomplished by passing options when you create the association. For example, this association uses two such options:
 
 ```ruby
 class Supplier < ActiveRecord::Base
@@ -1143,7 +1143,7 @@ When you declare a `has_many` association, the declaring class automatically gai
 * `collection.build(attributes = {}, ...)`
 * `collection.create(attributes = {})`
 
-In all of these methods, `collection` is replaced with the symbol passed as the first argument to `has_many`, and `collection_singular` is replaced with the singularized version of that symbol.. For example, given the declaration:
+In all of these methods, `collection` is replaced with the symbol passed as the first argument to `has_many`, and `collection_singular` is replaced with the singularized version of that symbol. For example, given the declaration:
 
 ```ruby
 class Customer < ActiveRecord::Base
@@ -1286,7 +1286,7 @@ The `collection.create` method returns a new object of the associated type. This
 
 #### Options for `has_many`
 
-While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `has_many` association reference. Such customizations can easily be accomplished by passing options when you create the association. For example, this assocation uses two such options:
+While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `has_many` association reference. Such customizations can easily be accomplished by passing options when you create the association. For example, this association uses two such options:
 
 ```ruby
 class Customer < ActiveRecord::Base
@@ -1737,7 +1737,7 @@ The `collection.create` method returns a new object of the associated type. This
 
 #### Options for `has_and_belongs_to_many`
 
-While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `has_and_belongs_to_many` association reference. Such customizations can easily be accomplished by passing options when you create the association. For example, this assocation uses two such options:
+While Rails uses intelligent defaults that will work well in most situations, there may be times when you want to customize the behavior of the `has_and_belongs_to_many` association reference. Such customizations can easily be accomplished by passing options when you create the association. For example, this association uses two such options:
 
 ```ruby
 class Parts < ActiveRecord::Base