diff --git a/core/modules/comment/lib/Drupal/comment/Tests/CommentLanguageTest.php b/core/modules/comment/lib/Drupal/comment/Tests/CommentLanguageTest.php
index 9255b34..c76dd41 100644
--- a/core/modules/comment/lib/Drupal/comment/Tests/CommentLanguageTest.php
+++ b/core/modules/comment/lib/Drupal/comment/Tests/CommentLanguageTest.php
@@ -76,7 +76,7 @@ function setUp() {
     $field = field_info_field('comment', 'comment_body');
     $field->translatable = TRUE;
     $field->save();
-    $this->assertTrue(field_is_translatable('comment', $field), 'Comment body is translatable.');
+    $this->assertTrue($field->isTranslatable(), 'Comment body is translatable.');
   }
 
   /**
diff --git a/core/modules/content_translation/lib/Drupal/content_translation/FieldTranslationSynchronizer.php b/core/modules/content_translation/lib/Drupal/content_translation/FieldTranslationSynchronizer.php
index 8486b16..4efde31 100644
--- a/core/modules/content_translation/lib/Drupal/content_translation/FieldTranslationSynchronizer.php
+++ b/core/modules/content_translation/lib/Drupal/content_translation/FieldTranslationSynchronizer.php
@@ -53,22 +53,19 @@ public function synchronizeFields(ContentEntityInterface $entity, $sync_langcode
       return;
     }
 
-    // @todo Use Entity Field API to retrieve field definitions.
-    $instances = field_info_instances($entity_type, $entity->bundle());
-    foreach ($instances as $field_name => $instance) {
-      $field = $instance->getField();
+    foreach ($entity as $field_name => $items) {
+      $field_definition = $items->getFieldDefinition();
 
-      // Sync when the field is not empty, when the synchronization translations
-      // setting is set, and the field is translatable.
-      $translation_sync = $instance->getSetting('translation_sync');
-      if (!$entity->get($field_name)->isEmpty() && !empty($translation_sync) && field_is_translatable($entity_type, $field)) {
+      // Sync if the field is translatable, not empty, and the synchronization
+      // setting is enabled.
+      if ($field_definition->isTranslatable() && !$items->isEmpty() && $translation_sync = $field_definition->getSetting('translation_sync')) {
         // Retrieve all the untranslatable column groups and merge them into
         // single list.
         $groups = array_keys(array_diff($translation_sync, array_filter($translation_sync)));
         if (!empty($groups)) {
           $columns = array();
           foreach ($groups as $group) {
-            $column_groups = $field->getSetting('column_groups');
+            $column_groups = $field_definition->getSetting('column_groups');
             $info = $column_groups[$group];
             // A missing 'columns' key indicates we have a single-column group.
             $columns = array_merge($columns, isset($info['columns']) ? $info['columns'] : array($group));
diff --git a/core/modules/field/field.multilingual.inc b/core/modules/field/field.multilingual.inc
index 8565e96..d5d058a 100644
--- a/core/modules/field/field.multilingual.inc
+++ b/core/modules/field/field.multilingual.inc
@@ -30,9 +30,7 @@
  *
  * The available language codes for a particular field are returned by
  * field_available_languages(). Whether a field is translatable is determined by
- * calling field_is_translatable(), which checks the $field['translatable']
- * property returned by field_info_field() and whether the entity type the field
- * is attached to supports translation.
+ * calling $field_definition->isTranslatable().
  *
  * By default, field_invoke_method() processes a field in all available
  * languages, unless it is given a language code suggestion. Based on that
@@ -93,7 +91,7 @@ function field_available_languages($entity_type, FieldInterface $field) {
   if (!isset($field_langcodes[$entity_type][$field_name])) {
     // If the field has language support enabled we retrieve an (alterable) list
     // of enabled languages, otherwise we return Language::LANGCODE_DEFAULT.
-    if (field_is_translatable($entity_type, $field)) {
+    if ($field->isTranslatable()) {
       $langcodes = field_content_languages();
       // Let other modules alter the available languages.
       $context = array('entity_type' => $entity_type, 'field' => $field);
@@ -153,24 +151,6 @@ function field_content_languages() {
 }
 
 /**
- * Checks whether a field has language support.
- *
- * A field has language support enabled if its 'translatable' property is set to
- * TRUE, and its entity type has at least one translation handler registered.
- *
- * @param $entity_type
- *   The type of the entity the field is attached to.
- * @param $field
- *   A field data structure.
- *
- * @return
- *   TRUE if the field can be translated.
- */
-function field_is_translatable($entity_type, FieldInterface $field) {
-  return $field->isTranslatable() && field_has_translation_handler($entity_type);
-}
-
-/**
  * Checks if a module is registered as a translation handler for a given entity.
  *
  * If no handler is passed, the function simply checks if there is any
diff --git a/core/modules/field/lib/Drupal/field/Plugin/views/field/Field.php b/core/modules/field/lib/Drupal/field/Plugin/views/field/Field.php
index 9bbb6ca..2a3b8fd 100644
--- a/core/modules/field/lib/Drupal/field/Plugin/views/field/Field.php
+++ b/core/modules/field/lib/Drupal/field/Plugin/views/field/Field.php
@@ -252,7 +252,7 @@ public function query($use_groupby = FALSE) {
 
       // Filter by langcode, if field translation is enabled.
       $field = $this->field_info;
-      if (field_is_translatable($entity_type, $field) && !empty($this->view->display_handler->options['field_langcode_add_to_query'])) {
+      if ($field->isTranslatable() && !empty($this->view->display_handler->options['field_langcode_add_to_query'])) {
         $column = $this->tableAlias . '.langcode';
         // By the same reason as field_language the field might be Language::LANGCODE_NOT_SPECIFIED in reality so allow it as well.
         // @see this::field_langcode()
@@ -855,7 +855,7 @@ protected function addSelfTokens(&$tokens, $item) {
    * according to the settings.
    */
   function field_langcode(EntityInterface $entity) {
-    if (field_is_translatable($entity->entityType(), $this->field_info)) {
+    if ($this->field_info->isTranslatable()) {
       $default_langcode = language_default()->id;
       $langcode = str_replace(
         array('***CURRENT_LANGUAGE***', '***DEFAULT_LANGUAGE***'),