diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
index 3834dae..5522c3f 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
@@ -357,18 +357,14 @@ protected function setStaticCache(array $entities) {
   }
 
   /**
-   * Invokes a hook on behalf of the entity.
-   *
-   * @param $hook
-   *   One of 'presave', 'insert', 'update', 'predelete', or 'delete'.
-   * @param $entity
-   *   The entity object.
+   * {@inheritdoc}
    */
-  protected function invokeHook($hook, EntityInterface $entity) {
+  protected function invokeHook($hook, EntityInterface $entity, array $args = []) {
+    array_unshift($args, $entity, $this->entityTypeId);
     // Invoke the hook.
-    $this->moduleHandler->invokeAll($this->entityTypeId . '_' . $hook, array($entity));
+    $this->moduleHandler->invokeAll($this->entityTypeId . '_' . $hook, $args);
     // Invoke the respective entity-level hook.
-    $this->moduleHandler->invokeAll('entity_' . $hook, array($entity, $this->entityTypeId));
+    $this->moduleHandler->invokeAll('entity_' . $hook, $args);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php b/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
index afdce40..644337b 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
@@ -128,13 +128,26 @@ protected function initFieldValues(ContentEntityInterface $entity, array $values
    * {@inheritdoc}
    */
   public function createTranslation(ContentEntityInterface $entity, $langcode, array $values = []) {
+    // The source translation language could be estimated from the $values in
+    // the case that the translation has been added through
+    // $entity->addTranslation($langcode, $entity_src_translation->toArray()).
+    if (isset($values[$this->langcodeKey])) {
+      if (isset($values[$this->langcodeKey][0]['value'])) {
+        $src_langcode = $values[$this->langcodeKey][0]['value'];
+      }
+      elseif (!is_array($values[$this->langcodeKey])) {
+        $src_langcode = $values[$this->langcodeKey];
+      }
+    }
+    $src_langcode = isset($src_langcode) && $entity->hasTranslation($src_langcode) ? $src_langcode : NULL;
+
     $translation = $entity->getTranslation($langcode);
     $definitions = array_filter($translation->getFieldDefinitions(), function(FieldDefinitionInterface $definition) { return $definition->isTranslatable(); });
     $field_names = array_map(function(FieldDefinitionInterface $definition) { return $definition->getName(); }, $definitions);
     $values[$this->langcodeKey] = $langcode;
     $values[$this->getEntityType()->getKey('default_langcode')] = FALSE;
     $this->initFieldValues($translation, $values, $field_names);
-    $this->invokeHook('translation_create', $translation);
+    $this->invokeHook('translation_create', $translation, [$src_langcode]);
     return $translation;
   }
 
@@ -398,7 +411,7 @@ protected function invokeStorageLoadHook(array &$entities) {
   /**
    * {@inheritdoc}
    */
-  protected function invokeHook($hook, EntityInterface $entity) {
+  protected function invokeHook($hook, EntityInterface $entity, array $args = []) {
     /** @var \Drupal\Core\Entity\ContentEntityInterface $entity */
 
     switch ($hook) {
@@ -415,7 +428,7 @@ protected function invokeHook($hook, EntityInterface $entity) {
         break;
     }
 
-    parent::invokeHook($hook, $entity);
+    parent::invokeHook($hook, $entity, $args);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Entity/EntityStorageBase.php b/core/lib/Drupal/Core/Entity/EntityStorageBase.php
index f583121..d2a5361 100644
--- a/core/lib/Drupal/Core/Entity/EntityStorageBase.php
+++ b/core/lib/Drupal/Core/Entity/EntityStorageBase.php
@@ -161,12 +161,15 @@ protected function setStaticCache(array $entities) {
    *   'revision_delete'.
    * @param \Drupal\Core\Entity\EntityInterface $entity
    *   The entity object.
+   * @param array $args
+   *   Other arguments to pass to the hook beside the entity.
    */
-  protected function invokeHook($hook, EntityInterface $entity) {
+  protected function invokeHook($hook, EntityInterface $entity, array $args = []) {
+    array_unshift($args, $entity);
     // Invoke the hook.
-    $this->moduleHandler()->invokeAll($this->entityTypeId . '_' . $hook, array($entity));
+    $this->moduleHandler()->invokeAll($this->entityTypeId . '_' . $hook, $args);
     // Invoke the respective entity-level hook.
-    $this->moduleHandler()->invokeAll('entity_' . $hook, array($entity));
+    $this->moduleHandler()->invokeAll('entity_' . $hook, $args);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Entity/entity.api.php b/core/lib/Drupal/Core/Entity/entity.api.php
index 9f6ef8b..c8e981d 100644
--- a/core/lib/Drupal/Core/Entity/entity.api.php
+++ b/core/lib/Drupal/Core/Entity/entity.api.php
@@ -1029,11 +1029,15 @@ function hook_ENTITY_TYPE_update(Drupal\Core\Entity\EntityInterface $entity) {
  *
  * @param \Drupal\Core\Entity\EntityInterface $translation
  *   The entity object.
+ * @param string|NULL $source_langcode
+ *   The source language code from which the entity has been translated. It
+ *   will be set only if the source translation could be determined by the
+ *   storage.
  *
  * @ingroup entity_crud
  * @see hook_ENTITY_TYPE_translation_create()
  */
-function hook_entity_translation_create(\Drupal\Core\Entity\EntityInterface $translation) {
+function hook_entity_translation_create(\Drupal\Core\Entity\EntityInterface $translation, $source_langcode = NULL) {
   \Drupal::logger('example')->info('Entity translation created: @label', ['@label' => $translation->label()]);
 }
 
@@ -1045,11 +1049,15 @@ function hook_entity_translation_create(\Drupal\Core\Entity\EntityInterface $tra
  *
  * @param \Drupal\Core\Entity\EntityInterface $translation
  *   The entity object.
+ * @param string|NULL $source_langcode
+ *   The source language code from which the entity has been translated. It
+ *   will be set only if the source translation could be determined by the
+ *   storage.
  *
  * @ingroup entity_crud
  * @see hook_entity_translation_create()
  */
-function hook_ENTITY_TYPE_translation_create(\Drupal\Core\Entity\EntityInterface $translation) {
+function hook_ENTITY_TYPE_translation_create(\Drupal\Core\Entity\EntityInterface $translation, $source_langcode = NULL) {
   \Drupal::logger('example')->info('ENTITY_TYPE translation created: @label', ['@label' => $translation->label()]);
 }