diff -u b/core/lib/Drupal/Core/Language/Language.php b/core/lib/Drupal/Core/Language/Language.php
--- b/core/lib/Drupal/Core/Language/Language.php
+++ b/core/lib/Drupal/Core/Language/Language.php
@@ -70,11 +70,10 @@
   /**
    * The language negotiation method used when a language was detected.
    *
-   * The method ID, for example, LanguageNegotiatorInterface::METHOD_ID.
+   * The method ID, for example
+   * \Drupal\language\LanguageNegotiatorInterface::METHOD_ID.
    *
    * @var string
-   *
-   * @see language_types_initialize()
    */
   public $method_id;
 
@@ -90,7 +89,7 @@
   public $locked = FALSE;
 
   /**
-   * Builds the default language object.
+   * Constructs a new class instance.
    *
    * @param array $options
    *   The properties used to construct the language.
diff -u b/core/lib/Drupal/Core/Language/LanguageInterface.php b/core/lib/Drupal/Core/Language/LanguageInterface.php
--- b/core/lib/Drupal/Core/Language/LanguageInterface.php
+++ b/core/lib/Drupal/Core/Language/LanguageInterface.php
@@ -97,18 +97,18 @@
   const DIRECTION_RTL = 1;
 
   /**
-   * Gets the name of the Language object.
+   * Gets the name of the language.
    *
    * @return string
-   *   The human readable English name of the Language.
+   *   The human-readable English name of the language.
    */
   public function getName();
 
   /**
-   * Sets the name.
+   * Sets the name of the language.
    *
    * @param string $name
-   *   The human readable English name of the Language.
+   *   The human-readable English name of the language.
    *
    * @return $this
    */
@@ -118,7 +118,7 @@
    * Gets the ID (language code).
    *
    * @return string
-   *   The langcode.
+   *   The language code.
    */
   public function getId();
 
@@ -126,7 +126,7 @@
    * Sets the ID (language code).
    *
    * @param string $id
-   *   The langcode.
+   *   The language code.
    *
    * @return $this
    */
@@ -182,7 +182,7 @@
    * Sets whether this language is the default language.
    *
    * @param bool $default
-   *   True if it is the default language.
+   *   TRUE if it is the default language.
    *
    * @return $this
    */
@@ -192,7 +192,8 @@
    * Gets the language negotiation method ID for this language.
    *
    * @return string
-   *   The method ID, for example, LanguageNegotiatorInterface::METHOD_ID.
+   *   The method ID, for example
+   *   \Drupal\language\LanguageNegotiatorInterface::METHOD_ID.
    */
   public function getNegotiationMethodId();
 
@@ -200,7 +201,8 @@
    * Sets the language negotiation method ID for this language.
    *
    * @param string $method_id
-   *   The method ID, for example, LanguageNegotiatorInterface::METHOD_ID.
+   *   The method ID, for example
+   *   \Drupal\language\LanguageNegotiatorInterface::METHOD_ID.
    *
    * @return $this
    */
diff -u b/core/tests/Drupal/Tests/Core/Language/LanguageUnitTest.php b/core/tests/Drupal/Tests/Core/Language/LanguageUnitTest.php
--- b/core/tests/Drupal/Tests/Core/Language/LanguageUnitTest.php
+++ b/core/tests/Drupal/Tests/Core/Language/LanguageUnitTest.php
@@ -12,7 +12,7 @@
 use Drupal\Tests\UnitTestCase;
 
 /**
- * Tests \Drupal\Core\Language\Language.
+ * @coversDefaultClass \Drupal\Core\Language\Language
  *
  * @group Drupal
  * @group Language
@@ -47,8 +47,8 @@
   /**
    * Tests name getter and setter methods.
    *
-   * @covers \Drupal\Core\Language\Language::getName()
-   * @covers \Drupal\Core\Language\Language::setName()
+   * @covers ::getName()
+   * @covers ::setName()
    */
   public function testGetName() {
     $name = $this->randomName();
@@ -59,8 +59,8 @@
   /**
    * Tests langcode ID getter and setter methods.
    *
-   * @covers \Drupal\Core\Language\Language::getId()
-   * @covers \Drupal\Core\Language\Language::setId()
+   * @covers ::getId()
+   * @covers ::setId()
    */
   public function testGetLangcode() {
     $language_code = $this->randomName(2);
@@ -71,8 +71,8 @@
   /**
    * Tests direction getter and setter methods.
    *
-   * @covers \Drupal\Core\Language\Language::getDirection()
-   * @covers \Drupal\Core\Language\Language::setDirection()
+   * @covers ::getDirection()
+   * @covers ::setDirection()
    */
   public function testGetDirection() {
     $direction = LanguageInterface::DIRECTION_RTL;
@@ -83,8 +83,8 @@
   /**
    * Tests isDefault() and default setter.
    *
-   * @covers \Drupal\Core\Language\Language::isDefault()
-   * @covers \Drupal\Core\Language\Language::setDefault()
+   * @covers ::isDefault()
+   * @covers ::setDefault()
    */
   public function testIsDefault() {
     $default = TRUE;
@@ -95,8 +95,8 @@
   /**
    * Tests negotiationMethodId getter and setter methods.
    *
-   * @covers \Drupal\Core\Language\Language::getNegotiationMethodId()
-   * @covers \Drupal\Core\Language\Language::setNegotiationMethodId()
+   * @covers ::getNegotiationMethodId()
+   * @covers ::setNegotiationMethodId()
    */
   public function testGetNegotiationMethodId() {
     $method_id = $this->randomName();