diff -u b/core/modules/user/tests/src/Functional/UserPasswordResetTest.php b/core/modules/user/tests/src/Functional/UserPasswordResetTest.php
--- b/core/modules/user/tests/src/Functional/UserPasswordResetTest.php
+++ b/core/modules/user/tests/src/Functional/UserPasswordResetTest.php
@@ -215,48 +215,65 @@
 
   /**
    * Tests password reset functionality when user has set preferred language.
+   * 
+   * @dataProvider languagePrefixTestProvider
    */
-  public function testUserPasswordResetPreferredLanguage() {
+  public function testUserPasswordResetPreferredLanguage($setPreferredLangcode, $actualPreferredLangcode, $activeLangcode, $prefix, $visitingUrl, $expectedResetUrl, $unexpectedResetUrl) {
     // Set two new languages.
     ConfigurableLanguage::createFromLangcode('fr')->save();
     ConfigurableLanguage::createFromLangcode('zh-hant')->save();
 
     $this->languageManager = \Drupal::languageManager();
 
-    $default_language_code = $this->languageManager->getDefaultLanguage()->getId();
-
-    // Test password reset when language prefixes are not set.
-    $this->assertLanguagePrefixResetUrl('user/password', '/user/reset', "$default_language_code/user/reset");
-
     // Set language prefixes.
     $config = $this->config('language.negotiation');
     $config->set('url.prefixes', ['en' => '', 'fr' => 'fr', 'zh-hant' => 'zh'])->save();
     \Drupal::configFactory()->reset('language.negotiation');
     $this->rebuildContainer();
 
-    $this->drupalGet('zh/user/password');
-    $this->assertLangcodeDifferent('zh-hant', 'en');
-
-    // Set preferred language for user account.
-    $this->account->preferred_langcode = 'fr';
+    $this->account->preferred_langcode = $setPreferredLangcode;
     $this->account->save();
-    $this->assertSame('fr', $this->account->getPreferredLangcode());
+    $this->assertSame($actualPreferredLangcode, $this->account->getPreferredLangcode(FALSE));
 
-    // Test reset URL respects preferred language over other language settings.
-    $this->assertLanguagePrefixResetUrl('zh/user/password', '/fr/user/reset', '/zh/user/reset');
-
-    // Unset preferred language for user account.
-    $this->account->preferred_langcode = NULL;
-    $this->account->save();
-    $this->assertSame('', $this->account->getPreferredLangcode(FALSE));
-
-    // Test reset URL respect default language over browser language when
-    // preferred language is no set.
-    $this->assertLanguagePrefixResetUrl('zh/user/password', '/user/reset', '/zh/user/reset');
-
-    // Unset language prefixes.
-    $config = $this->config('language.negotiation');
-    $config->set('url.prefixes', [])->save();
+    // Test Default langcode is different from active langcode when visiting different.
+    if ($setPreferredLangcode !== 'en') {
+      $this->assertLangcodeDifferent($prefix, $activeLangcode, 'en');
+    }
+    
+    // Test password reset with language prefixes.
+    $this->assertLanguagePrefixResetUrl($visitingUrl, $expectedResetUrl, $unexpectedResetUrl);
+  }
+  
+  public function languagePrefixTestProvider() {
+    return [
+      'Test preferredLanguage not set' => [
+        'setPreferredLangcode' => 'en',
+        'actualPreferredLangcode' => 'en',
+        'activeLangcode' => 'en',
+        'prefix' => '',
+        'visitingUrl' => 'user/password',
+        'expectedResetUrl' => 'user/reset',
+        'unexpectedResetUrl' => 'en/user/reset'
+      ],
+      'Test language prefix set as fr, visiting zh' => [
+        'setPreferredLangcode' => 'fr',
+        'actualPreferredLangcode' => 'fr',
+        'activeLangcode' => 'fr',
+        'prefix' => 'fr',
+        'visitingUrl' => 'zh/user/password',
+        'expectedResetUrl' => 'fr/user/reset',
+        'unexpectedResetUrl' => 'zh/user/reset'
+      ],
+      'Test language prefix set as null, visiting zh' => [
+        'setPreferredLangcode' => 'null',
+        'actualPreferredLangcode' => '',
+        'activeLangcode' => 'zh-hant',
+        'prefix' => 'zh',
+        'visitingUrl' => 'zh/user/password',
+        'expectedResetUrl' => 'user/reset',
+        'unexpectedResetUrl' => 'zh/user/reset'
+      ],
+    ];
   }
 
   /**
@@ -282,14 +299,17 @@
 
   /**
    * Helper method to assert expected active language and
-   * default lanugage is different.
+   * default language is different.
    *
+   * @param string $prefix
+   *   The prefix to visit /user/password.
    * @param string $activeLangcode
    *   The active language code of your current session.
    * @param string $defaultLangcode
    *   The default language code of your site settings.
    */
-  public function assertLangcodeDifferent($activeLangcode, $defaultLangcode) {
+  public function assertLangcodeDifferent($prefix, $activeLangcode, $defaultLangcode) {
+    $this->drupalGet( $prefix . '/user/password');
     $this->assertSame($activeLangcode, $this->drupalGetHeader('Content-language'));
     $this->assertSame($defaultLangcode, $this->languageManager->getDefaultLanguage()->getId());
     $this->assertNotSame($this->languageManager->getDefaultLanguage()->getId(), $this->drupalGetHeader('Content-language'));