diff --git a/core/lib/Drupal/Core/Config/Entity/Query/QueryFactory.php b/core/lib/Drupal/Core/Config/Entity/Query/QueryFactory.php
index c696449..35bc2fd 100644
--- a/core/lib/Drupal/Core/Config/Entity/Query/QueryFactory.php
+++ b/core/lib/Drupal/Core/Config/Entity/Query/QueryFactory.php
@@ -36,7 +36,7 @@ public function __construct(StorageInterface $config_storage) {
   }
 
   /**
-   * Instantiate a entity query for a certain entity type.
+   * Instantiates an entity query for a given entity type.
    *
    * @param string $entity_type
    *   The entity type for the query.
diff --git a/core/lib/Drupal/Core/Entity/Query/QueryAggregateInterface.php b/core/lib/Drupal/Core/Entity/Query/QueryAggregateInterface.php
index 4cab897..486c246 100644
--- a/core/lib/Drupal/Core/Entity/Query/QueryAggregateInterface.php
+++ b/core/lib/Drupal/Core/Entity/Query/QueryAggregateInterface.php
@@ -13,8 +13,9 @@
 interface QueryAggregateInterface extends QueryInterface {
 
   /**
-   * Specify a field and a function to aggregate on. Available functions:
-   * SUM, AVG, MIN, MAX and COUNT.
+   * Specifies a field and a function to aggregate on.
+   *
+   * Available functions: SUM, AVG, MIN, MAX and COUNT.
    *
    * @todo What about GROUP_CONCAT support?
    *
@@ -33,7 +34,7 @@
   public function aggregate($field, $function, $langcode = NULL, &$alias = NULL);
 
   /**
-   * Specify the field to group on.
+   * Specifies the field to group on.
    *
    * @param string $field
    *   The name of the field to group by.
@@ -44,7 +45,7 @@ public function aggregate($field, $function, $langcode = NULL, &$alias = NULL);
   public function groupBy($field);
 
   /**
-   * Set a condition for an aggregated value.
+   * Sets a condition for an aggregated value.
    *
    * @param string $field
    *   The name of the field to aggregate by.
diff --git a/core/lib/Drupal/Core/Entity/Query/QueryBase.php b/core/lib/Drupal/Core/Entity/Query/QueryBase.php
index 9748f4c..c3c6932 100644
--- a/core/lib/Drupal/Core/Entity/Query/QueryBase.php
+++ b/core/lib/Drupal/Core/Entity/Query/QueryBase.php
@@ -38,7 +38,7 @@
   /**
    * Conditions.
    *
-   * @var ConditionInterface
+   * @var \Drupal\Core\Entity\Query\ConditionInterface
    */
   protected $condition;
 
@@ -59,7 +59,7 @@
   /**
    * Aggregate Conditions
    *
-   * @var ConditionAggregateInterface
+   * @var \Drupal\Core\Entity\Query\ConditionAggregateInterface
    */
   protected $conditionAggregate;
 
diff --git a/core/modules/field_sql_storage/lib/Drupal/field_sql_storage/Entity/Query.php b/core/modules/field_sql_storage/lib/Drupal/field_sql_storage/Entity/Query.php
index cfb8393..9d8ab5d 100644
--- a/core/modules/field_sql_storage/lib/Drupal/field_sql_storage/Entity/Query.php
+++ b/core/modules/field_sql_storage/lib/Drupal/field_sql_storage/Entity/Query.php
@@ -260,7 +260,7 @@ protected function finish() {
   }
 
   /**
-   * Creates the result by executing the query and return the result.
+   * Executes the query and returns the result.
    *
    * @return int|array
    *   Returns the query result as entity IDs.
@@ -289,7 +289,7 @@ protected function getSqlField($field, $langcode) {
   }
 
   /**
-   * Does the query requires GROUP BY and ORDER BY MIN/MAX.
+   * Returns whether the query requires GROUP BY and ORDER BY MIN/MAX.
    *
    * @return bool
    */
@@ -300,7 +300,7 @@ protected function isSimpleQuery() {
   /**
    * Implements the magic __clone method.
    *
-   * Zero out fields and GROUP BY when cloning.
+   * Reset fields and GROUP BY when cloning.
    */
   public function __clone() {
     parent::__clone();
diff --git a/core/modules/field_sql_storage/lib/Drupal/field_sql_storage/Entity/QueryAggregate.php b/core/modules/field_sql_storage/lib/Drupal/field_sql_storage/Entity/QueryAggregate.php
index 3b005eb..c8bbb81 100644
--- a/core/modules/field_sql_storage/lib/Drupal/field_sql_storage/Entity/QueryAggregate.php
+++ b/core/modules/field_sql_storage/lib/Drupal/field_sql_storage/Entity/QueryAggregate.php
@@ -23,7 +23,7 @@ class QueryAggregate extends Query implements QueryAggregateInterface {
   protected $sqlExpressions = array();
 
   /**
-   * Implements \Drupal\Core\Entity\Query\QueryAggregateInterface::execute()
+   * Implements \Drupal\Core\Entity\Query\QueryAggregateInterface::execute().
    */
   public function execute() {
     return $this
@@ -49,7 +49,7 @@ public function prepare() {
   }
 
   /**
-   * Implements \Drupal\Core\Entity\Query\QueryAggregateInterface::conditionAggregateGroupFactory()
+   * Implements \Drupal\Core\Entity\Query\QueryAggregateInterface::conditionAggregateGroupFactory().
    */
   public function conditionAggregateGroupFactory($conjunction = 'AND') {
     return new ConditionAggregate($conjunction);
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php
index e039b00..b957675 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php
@@ -66,8 +66,6 @@ protected function setUp() {
     $this->factory = $this->container->get('entity.query');
 
     // Add some fieldapi fields to be used in the test.
-
-    // @todo Maybe start from 0.
     for ($i = 1; $i <= 2; $i++) {
       $field = array(
         'field_name' => 'field_test_' . $i,
@@ -139,7 +137,7 @@ protected function setUp() {
    * Test aggregation support.
    */
   public function testAggregation() {
-    // Apply just a simple groupby.
+    // Apply a simple groupby.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->groupBy('user_id')
       ->execute();
@@ -157,7 +155,7 @@ public function testAggregation() {
     $function_expected['sum'] = array(array('id_sum' => 21));
     $function_expected['avg'] = array(array('id_avg' => (21.0/6.0)));
 
-    // Apply just a simple aggregation for different aggregation functions.
+    // Apply a simple aggregation for different aggregation functions.
     foreach ($function_expected as $aggregation_function => $expected) {
       $this->queryResult = $this->factory->getAggregate('entity_test')
         ->aggregate('id', $aggregation_function)
@@ -255,7 +253,7 @@ public function testAggregation() {
       array('user_id' => 2, 'id_count' => 3),
     ));
 
-    // Apply aggregation, groupby, a aggregation condition and a sort with the
+    // Apply aggregation, groupby, an aggregation condition and a sort with the
     // operator '='.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->aggregate('id', 'COUNT')
@@ -265,7 +263,7 @@ public function testAggregation() {
       ->execute();
     $this->assertSortedResults(array(array('id_count' => 2, 'user_id' => 3)));
 
-    // Apply aggregation, groupby, a aggregation condition and a sort with the
+    // Apply aggregation, groupby, an aggregation condition and a sort with the
     // operator '<' and order ASC.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->aggregate('id', 'COUNT')
@@ -278,7 +276,7 @@ public function testAggregation() {
       array('id_count' => 2, 'user_id' => 3),
     ));
 
-    // Apply aggregation, groupby, a aggregation condition and a sort with the
+    // Apply aggregation, groupby, an aggregation condition and a sort with the
     // operator '<' and order DESC.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->aggregate('id', 'COUNT')
@@ -385,7 +383,7 @@ public function testAggregation() {
       array('field_test_1' => 3, 'field_test_2_count' => 1, 'field_test_2_sum' => 8),
     ));
 
-    // Apply a aggregate condition for a fieldapi field and group by a simple
+    // Apply an aggregate condition for a fieldapi field and group by a simple
     // property.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->conditionAggregate('field_test_1', 'COUNT', 3)
@@ -406,7 +404,7 @@ public function testAggregation() {
       array('user_id' => 3, 'field_test_1_sum' => 5, 'field_test_1_count' => 2),
     ));
 
-    // Apply a aggregate condition for a simple property and a group by a
+    // Apply an aggregate condition for a simple property and a group by a
     // fieldapi field.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->conditionAggregate('user_id', 'COUNT', 2)
@@ -425,7 +423,7 @@ public function testAggregation() {
       array('field_test_1' => 2, 'user_id_count' => 3),
     ));
 
-    // Apply a aggregate condition and a group by fieldapi fields.
+    // Apply an aggregate condition and a group by fieldapi fields.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->groupBy('field_test_1')
       ->conditionAggregate('field_test_2', 'COUNT', 2)
@@ -442,7 +440,7 @@ public function testAggregation() {
       array('field_test_1' => 2, 'field_test_2_count' => 3),
     ));
 
-    // Apply a aggregate condition and a group by fieldapi fields with multiple
+    // Apply an aggregate condition and a group by fieldapi fields with multiple
     // conditions via AND.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->groupBy('field_test_1')
@@ -451,7 +449,7 @@ public function testAggregation() {
       ->execute();
     $this->assertResults(array());
 
-    // Apply a aggregate condition and a group by fieldapi fields with multiple
+    // Apply an aggregate condition and a group by fieldapi fields with multiple
     // conditions via OR.
     $this->queryResult = $this->factory->getAggregate('entity_test', 'OR')
       ->groupBy('field_test_1')
@@ -463,8 +461,8 @@ public function testAggregation() {
       array('field_test_1' => 3, 'field_test_2_count' => 1, 'field_test_2_sum' => 8),
     ));
 
-    // Group by a normal property and aggregate a fieldapi field and sort by
-    // the groupby field.
+    // Group by a normal property and aggregate a fieldapi field and sort by the
+    // groupby field.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->aggregate('field_test_1', 'COUNT')
       ->groupBy('user_id')
@@ -497,8 +495,8 @@ public function testAggregation() {
       array('user_id' => 3, 'field_test_1_count' => 2),
     ));
 
-    // Group by a normal property and aggregate a fieldapi field and sort by
-    // the aggregated field.
+    // Group by a normal property, aggregate a fieldapi field, and sort by the
+    // aggregated field.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->sortAggregate('field_test_1', 'COUNT', 'DESC')
       ->groupBy('user_id')
@@ -519,7 +517,7 @@ public function testAggregation() {
       array('user_id' => 2, 'field_test_1_count' => 3),
     ));
 
-    // Group by and aggregate by fieldapi fields and sort by the groupby field.
+    // Group by and aggregate by fieldapi field, and sort by the groupby field.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->groupBy('field_test_1')
       ->aggregate('field_test_2', 'COUNT')
@@ -542,7 +540,7 @@ public function testAggregation() {
       array('field_test_1' => 1, 'field_test_2_count' => 2),
     ));
 
-    // Groupy and aggregate by fieldapi fields and sort by the aggregated field.
+    // Groupy and aggregate by fieldapi field, and sort by the aggregated field.
     $this->queryResult = $this->factory->getAggregate('entity_test')
       ->groupBy('field_test_1')
       ->sortAggregate('field_test_2', 'COUNT', 'DESC')