diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index a8af37aa3aa3a811eee114d0d0fe3430442f41b9..98c1ed9291d5e976b2a854cde6b1b3f7b52e3940 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -1912,7 +1912,7 @@ function install_check_translations($langcode, $server_pattern) {
     }
   }
 
-  // If the translations directory does not exists, throw an error.
+  // If the translations directory does not exist, throw an error.
   if (!$translations_directory_exists) {
     $requirements['translations directory exists'] = [
       'title'       => t('Translations directory'),
diff --git a/core/lib/Drupal/Core/Archiver/ArchiveTar.php b/core/lib/Drupal/Core/Archiver/ArchiveTar.php
index 24085cea9fe6ef1b5580b50db6e1c889664fd55a..1570a1e83abe8d249cd5c2147a196df042cc06e7 100644
--- a/core/lib/Drupal/Core/Archiver/ArchiveTar.php
+++ b/core/lib/Drupal/Core/Archiver/ArchiveTar.php
@@ -577,7 +577,7 @@ public function addString($p_filename, $p_string, $p_datetime = false, $p_params
      * indicated by $p_path. When relevant the memorized path of the
      * files/dir can be modified by removing the $p_remove_path path at the
      * beginning of the file/dir path.
-     * While extracting a file, if the directory path does not exists it is
+     * While extracting a file, if the directory path does not exist it is
      * created.
      * While extracting a file, if the file already exists it is replaced
      * without looking for last modification date.
diff --git a/core/modules/aggregator/tests/src/Functional/DeleteFeedTest.php b/core/modules/aggregator/tests/src/Functional/DeleteFeedTest.php
index 7d7569628154cc0911ae7b5fe986039a155b45d1..557720658da2555fb0174c73ae88526b6dd97360 100644
--- a/core/modules/aggregator/tests/src/Functional/DeleteFeedTest.php
+++ b/core/modules/aggregator/tests/src/Functional/DeleteFeedTest.php
@@ -40,7 +40,7 @@ public function testDeleteFeed() {
 
     // Check feed source.
     $this->drupalGet('aggregator/sources/' . $feed1->id());
-    $this->assertResponse(404, 'Deleted feed source does not exists.');
+    $this->assertResponse(404, 'Deleted feed source does not exist.');
 
     // Check database for feed.
     $result = db_query("SELECT COUNT(*) FROM {aggregator_feed} WHERE title = :title AND url = :url", [':title' => $feed1->label(), ':url' => $feed1->getUrl()])->fetchField();
diff --git a/core/modules/field/src/Plugin/migrate/process/ProcessField.php b/core/modules/field/src/Plugin/migrate/process/ProcessField.php
index e96db6802582cf440ccb37c352d722995d5aa581..c68acc9272de66f768ef6a525f397d362d6e4f0c 100644
--- a/core/modules/field/src/Plugin/migrate/process/ProcessField.php
+++ b/core/modules/field/src/Plugin/migrate/process/ProcessField.php
@@ -147,7 +147,7 @@ protected function callMethodOnFieldPlugin(MigrateFieldPluginManagerInterface $f
     $plugin_id = $field_plugin_manager->getPluginIdFromFieldType($field_type, [], $this->migration);
     $plugin_instance = $field_plugin_manager->createInstance($plugin_id, [], $this->migration);
     if (!is_callable([$plugin_instance, $method])) {
-      throw new MigrateException('The specified method does not exists or is not callable.');
+      throw new MigrateException('The specified method does not exist or is not callable.');
     }
     return call_user_func_array([$plugin_instance, $method], [$row]);
   }
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 15138a10e574163de07ce56628fa6ab9833c4a1a..d6bc508dab644d77ffb71aeb722d177c5eac4882 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -918,7 +918,7 @@ function system_check_directory($form_element, FormStateInterface $form_state) {
 
   $logger = \Drupal::logger('file system');
   if (!is_dir($directory) && !drupal_mkdir($directory, NULL, TRUE)) {
-    // If the directory does not exists and cannot be created.
+    // If the directory does not exist and cannot be created.
     $form_state->setErrorByName($form_element['#parents'][0], t('The directory %directory does not exist and could not be created.', ['%directory' => $directory]));
     $logger->error('The directory %directory does not exist and could not be created.', ['%directory' => $directory]);
   }
diff --git a/core/modules/user/src/Plugin/migrate/process/UserLangcode.php b/core/modules/user/src/Plugin/migrate/process/UserLangcode.php
index 80f20783b62274f61bcc48ad83628dbdd6c2708b..5373dad671c39b982a8e4757a3153c170588aac5 100644
--- a/core/modules/user/src/Plugin/migrate/process/UserLangcode.php
+++ b/core/modules/user/src/Plugin/migrate/process/UserLangcode.php
@@ -74,7 +74,7 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
         return 'en';
       }
     }
-    // If the user's language does not exists, use the default language.
+    // If the user's language does not exist, use the default language.
     elseif ($this->languageManager->getLanguage($value) === NULL) {
       return $this->languageManager->getDefaultLanguage()->getId();
     }
diff --git a/core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php b/core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php
index 60c3754ffe391f8378ad981e8b010fc0161b7fbb..9cbd186420848c11f0eb40b1aea0bc91e80074e8 100644
--- a/core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php
@@ -93,7 +93,7 @@ public function testSchema() {
 
     // Test for fake index and test for the boolean result of indexExists().
     $index_exists = Database::getConnection()->schema()->indexExists('test_table', 'test_field');
-    $this->assertIdentical($index_exists, FALSE, 'Fake index does not exists');
+    $this->assertIdentical($index_exists, FALSE, 'Fake index does not exist');
     // Add index.
     db_add_index('test_table', 'test_field', ['test_field'], $table_specification);
     // Test for created index and test for the boolean result of indexExists().
diff --git a/core/tests/Drupal/Tests/WebAssert.php b/core/tests/Drupal/Tests/WebAssert.php
index 57358cde16c2ceca854d717b2b58301f2380c9f3..313952bfe80aace3589c85308e0642a28bee1abb 100644
--- a/core/tests/Drupal/Tests/WebAssert.php
+++ b/core/tests/Drupal/Tests/WebAssert.php
@@ -488,7 +488,7 @@ public function hiddenFieldExists($field, TraversableElement $container = NULL)
   }
 
   /**
-   * Checks that specific hidden field does not exists.
+   * Checks that specific hidden field does not exist.
    *
    * @param string $field
    *   One of id|name|value for the hidden field.