Index: wp-includes/rest-api/class-wp-rest-server.php
===================================================================
--- wp-includes/rest-api/class-wp-rest-server.php	(revision 35431)
+++ wp-includes/rest-api/class-wp-rest-server.php	(working copy)
@@ -812,7 +812,7 @@
 						if ( is_wp_error( $permission ) ) {
 							$response = $permission;
 						} else if ( false === $permission || null === $permission ) {
-							$response = new WP_Error( 'rest_forbidden', __( "You don't have permission to do this." ), array( 'status' => 403 ) );
+							$response = new WP_Error( 'rest_forbidden', __( 'You are not allowed to do this.' ), array( 'status' => 403 ) );
 						}
 					}
 				}
Index: wp-includes/revision.php
===================================================================
--- wp-includes/revision.php	(revision 35431)
+++ wp-includes/revision.php	(working copy)
@@ -523,7 +523,7 @@
 		$id = (int) $_GET['preview_id'];
 
 		if ( false === wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . $id ) )
-			wp_die( __('You do not have permission to preview drafts.') );
+			wp_die( __( 'You are not allowed to preview drafts.' ) );
 
 		add_filter('the_preview', '_set_preview');
 	}
Index: wp-includes/script-loader.php
===================================================================
--- wp-includes/script-loader.php	(revision 35431)
+++ wp-includes/script-loader.php	(working copy)
@@ -129,7 +129,7 @@
 
 	$scripts->add( 'wp-ajax-response', "/wp-includes/js/wp-ajax-response$suffix.js", array('jquery'), false, 1 );
 	did_action( 'init' ) && $scripts->localize( 'wp-ajax-response', 'wpAjax', array(
-		'noPerm' => __('You do not have permission to do that.'),
+		'noPerm' => __('You are not allowed to do that.'),
 		'broken' => __('An unidentified error has occurred.')
 	) );
 
@@ -476,7 +476,7 @@
 	if ( is_admin() ) {
 		$scripts->add( 'admin-tags', "/wp-admin/js/tags$suffix.js", array( 'jquery', 'wp-ajax-response' ), false, 1 );
 		did_action( 'init' ) && $scripts->localize( 'admin-tags', 'tagsl10n', array(
-			'noPerm' => __('You do not have permission to do that.'),
+			'noPerm' => __('You are not allowed to do that.'),
 			'broken' => __('An unidentified error has occurred.')
 		));