diff --git a/src/js/_enqueues/wp/customize/controls.js b/src/js/_enqueues/wp/customize/controls.js
index ca1529d20d..0a131d188f 100644
--- a/src/js/_enqueues/wp/customize/controls.js
+++ b/src/js/_enqueues/wp/customize/controls.js
@@ -3500,7 +3500,7 @@
 			control.params = _.extend(
 				{},
 				control.defaults,
-				control.params || {}, // In case sub-class already defines.
+				control.params || {}, // In case subclass already defines.
 				options.params || options || {} // The options.params property is deprecated, but it is checked first for back-compat.
 			);
 
diff --git a/src/wp-admin/includes/class-wp-list-table.php b/src/wp-admin/includes/class-wp-list-table.php
index d4f18f7f2a..d6fb8f0860 100644
--- a/src/wp-admin/includes/class-wp-list-table.php
+++ b/src/wp-admin/includes/class-wp-list-table.php
@@ -251,7 +251,7 @@ class WP_List_Table {
 	 * @abstract
 	 */
 	public function ajax_user_can() {
-		die( 'function WP_List_Table::ajax_user_can() must be over-ridden in a sub-class.' );
+		die( 'function WP_List_Table::ajax_user_can() must be overridden in a subclass.' );
 	}
 
 	/**
@@ -263,7 +263,7 @@ class WP_List_Table {
 	 * @abstract
 	 */
 	public function prepare_items() {
-		die( 'function WP_List_Table::prepare_items() must be over-ridden in a sub-class.' );
+		die( 'function WP_List_Table::prepare_items() must be overridden in a subclass.' );
 	}
 
 	/**
@@ -931,7 +931,7 @@ class WP_List_Table {
 	 * @return array
 	 */
 	public function get_columns() {
-		die( 'function WP_List_Table::get_columns() must be over-ridden in a sub-class.' );
+		die( 'function WP_List_Table::get_columns() must be overridden in a subclass.' );
 	}
 
 	/**
diff --git a/src/wp-includes/class-wp-image-editor.php b/src/wp-includes/class-wp-image-editor.php
index 7ee4440138..8baf341a6d 100644
--- a/src/wp-includes/class-wp-image-editor.php
+++ b/src/wp-includes/class-wp-image-editor.php
@@ -30,7 +30,7 @@ abstract class WP_Image_Editor {
 
 	/**
 	 * Checks to see if current environment supports the editor chosen.
-	 * Must be overridden in a sub-class.
+	 * Must be overridden in a subclass.
 	 *
 	 * @since 3.5.0
 	 *
@@ -45,7 +45,7 @@ abstract class WP_Image_Editor {
 
 	/**
 	 * Checks to see if editor supports the mime-type specified.
-	 * Must be overridden in a sub-class.
+	 * Must be overridden in a subclass.
 	 *
 	 * @since 3.5.0
 	 *
diff --git a/src/wp-includes/class-wp-widget.php b/src/wp-includes/class-wp-widget.php
index 89a42ae9f7..0b6959fb13 100644
--- a/src/wp-includes/class-wp-widget.php
+++ b/src/wp-includes/class-wp-widget.php
@@ -101,7 +101,7 @@ class WP_Widget {
 	/**
 	 * Echoes the widget content.
 	 *
-	 * Sub-classes should over-ride this function to generate their widget code.
+	 * Subclasses should override this function to generate their widget code.
 	 *
 	 * @since 2.8.0
 	 *
@@ -110,7 +110,7 @@ class WP_Widget {
 	 * @param array $instance The settings for the particular instance of the widget.
 	 */
 	public function widget( $args, $instance ) {
-		die( 'function WP_Widget::widget() must be over-ridden in a sub-class.' );
+		die( 'function WP_Widget::widget() must be overridden in a subclass.' );
 	}
 
 	/**
diff --git a/src/wp-includes/pomo/translations.php b/src/wp-includes/pomo/translations.php
index be9081a2fc..720f427b0d 100644
--- a/src/wp-includes/pomo/translations.php
+++ b/src/wp-includes/pomo/translations.php
@@ -113,7 +113,7 @@ if ( ! class_exists( 'Translations', false ) ) :
 		 * Here, in the base Translations class, the common logic for English is implemented:
 		 *  0 if there is one element, 1 otherwise
 		 *
-		 * This function should be overridden by the sub-classes. For example MO/PO can derive the logic
+		 * This function should be overridden by the subclasses. For example MO/PO can derive the logic
 		 * from their headers.
 		 *
 		 * @param integer $count number of items