diff --git a/core/lib/Drupal/Core/Database/Query/Condition.php b/core/lib/Drupal/Core/Database/Query/Condition.php
index 987fba85689c988a08385e5bee54d35ead93cf29..d32d00a23bb61219b0e14302eb1748793f1fe2c0 100644
--- a/core/lib/Drupal/Core/Database/Query/Condition.php
+++ b/core/lib/Drupal/Core/Database/Query/Condition.php
@@ -278,8 +278,9 @@ function __clone() {
    * @param $operator
    *   The condition operator, such as "IN", "BETWEEN", etc. Case-sensitive.
    *
-   * @return
-   *   The extra handling directives for the specified operator, or NULL.
+   * @return array
+   *   The extra handling directives for the specified operator or an empty
+   *   array if there are no extra handling directives.
    */
   protected function mapConditionOperator($operator) {
     // $specials does not use drupal_static as its value never changes.
diff --git a/core/lib/Drupal/Core/Database/Query/Insert.php b/core/lib/Drupal/Core/Database/Query/Insert.php
index 392c8c22e3f93e582ee1501d52f1e61bb5f22051..d9ddbc053e9dde31395cbd5e750deeca4ad0e7be 100644
--- a/core/lib/Drupal/Core/Database/Query/Insert.php
+++ b/core/lib/Drupal/Core/Database/Query/Insert.php
@@ -187,10 +187,10 @@ public function from(SelectInterface $query) {
    * Executes the insert query.
    *
    * @return
-   *   The last insert ID of the query, if one exists. If the query
-   *   was given multiple sets of values to insert, the return value is
-   *   undefined. If no fields are specified, this method will do nothing and
-   *   return NULL. That makes it safe to use in multi-insert loops.
+   *   The last insert ID of the query, if one exists. If the query was given
+   *   multiple sets of values to insert, the return value is undefined. If no
+   *   fields are specified, this method will do nothing and return NULL. That
+   *   That makes it safe to use in multi-insert loops.
    */
   public function execute() {
     // If validation fails, simply return NULL. Note that validation routines
diff --git a/core/lib/Drupal/Core/Database/Query/PagerSelectExtender.php b/core/lib/Drupal/Core/Database/Query/PagerSelectExtender.php
index 0f023e712726129b02b5e95de86758f387bdeb6a..6bd6fac04366d1d2a4a987e2abd3b2568d6cc494 100644
--- a/core/lib/Drupal/Core/Database/Query/PagerSelectExtender.php
+++ b/core/lib/Drupal/Core/Database/Query/PagerSelectExtender.php
@@ -135,8 +135,8 @@ public function getCountQuery() {
    *
    * The default if not specified is 10 items per page.
    *
-   * @param $limit
-   *   An integer specifying the number of elements per page.  If passed a false
+   * @param int|false $limit
+   *   An integer specifying the number of elements per page. If passed a false
    *   value (FALSE, 0, NULL), the pager is disabled.
    */
   public function limit($limit = 10) {
@@ -161,6 +161,7 @@ public function limit($limit = 10) {
    * if both are set explicitly.
    *
    * @param $element
+   *   Element ID that is used to differentiate different pager queries.
    */
   public function element($element) {
     $this->element = $element;