diff --git a/core/modules/system/lib/Drupal/system/Tests/Cache/GenericCacheBackendUnitTestBase.php b/core/modules/system/lib/Drupal/system/Tests/Cache/GenericCacheBackendUnitTestBase.php
index cd54288..95805d7 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Cache/GenericCacheBackendUnitTestBase.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Cache/GenericCacheBackendUnitTestBase.php
@@ -46,7 +46,7 @@
   protected $defaultValue;
 
   /**
-   * Gets testing bin.
+   * Gets the testing bin.
    *
    * Override this method if you want to work on a different bin than the
    * default one.
@@ -75,13 +75,13 @@ protected function getTestBin() {
   protected abstract function createCacheBackend($bin);
 
   /**
-   * Allows specific implementation to change the environement before test run.
+   * Allows specific implementation to change the environment before a test run.
    */
   public function setUpCacheBackend() {
   }
 
   /**
-   * Allows alteration of environment after test run but before tear down.
+   * Allows alteration of environment after a test run but before tear down.
    *
    * Used before the real tear down because the tear down will change things
    * such as the database prefix.
@@ -90,7 +90,7 @@ public function tearDownCacheBackend() {
   }
 
   /**
-   * Gets backend to test, this will get a shared instance set in the object.
+   * Gets a backend to test; this will get a shared instance set in the object.
    *
    * @return Drupal\Core\Cache\CacheBackendInterface
    *   Cache backend to test.
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/HtmlIdentifierUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/HtmlIdentifierUnitTest.php
index 1e78fd0..df4046c 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/HtmlIdentifierUnitTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/HtmlIdentifierUnitTest.php
@@ -10,7 +10,7 @@
 use Drupal\simpletest\UnitTestBase;
 
 /**
- * Tests the cleaning HTML identifiers.
+ * Tests cleaning HTML identifiers.
  */
 class HtmlIdentifierUnitTest extends UnitTestBase {
   public static function getInfo() {
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/SchemaTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/SchemaTest.php
index a6685ea..7c328b4 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/SchemaTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/SchemaTest.php
@@ -147,6 +147,12 @@ function testSchema() {
 
   /**
    * Tests inserting data into an existing table.
+   *
+   * @param $table
+   *   The database table to insert data into.
+   *
+   * @return
+   *   TRUE if the insert succeeded, FALSE otherwise.
    */
   function tryInsert($table = 'test_table') {
     try {
@@ -213,11 +219,12 @@ function testUnsignedColumns() {
    * Tries to insert a negative value into columns defined as unsigned.
    *
    * @param $table_name
-   *   The table to insert
+   *   The table to insert.
    * @param $column_name
-   *   The column to insert
+   *   The column to insert.
+   *
    * @return
-   *   TRUE if the insert succeeded, FALSE otherwise
+   *   TRUE if the insert succeeded, FALSE otherwise.
    */
   function tryUnsignedInsert($table_name, $column_name) {
     try {
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php
index 6aa08a2..39ed2b4 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php
@@ -56,6 +56,11 @@ function testLCustomClass() {
   /**
    * Checks for class existence in link.
    *
+   * @param $link
+   *   URL to search.
+   * @param $class
+   *   Element class to search for.
+   *
    * @return bool
    *   TRUE if the class is found, FALSE otherwise.
    */
diff --git a/core/modules/system/lib/Drupal/system/Tests/Database/SelectTableSortDefaultTest.php b/core/modules/system/lib/Drupal/system/Tests/Database/SelectTableSortDefaultTest.php
index 3ef8eaa..c740292 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Database/SelectTableSortDefaultTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Database/SelectTableSortDefaultTest.php
@@ -77,7 +77,7 @@ function testTableSortQueryFirst() {
   }
 
   /**
-   * Confirms that no error is thrown if no sort is not set in a tableselect.
+   * Confirms that no error is thrown if no sort is set in a tableselect.
    */
   function testTableSortDefaultSort() {
     $this->drupalGet('database_test/tablesort_default_sort');