change text username with email - Joomla! Forum - community, help and support

hello
in website possible users log-in username or e-mail.
i prefer use email, wuold change in placeholder or everywhere there text username "nome utente in italian" e-mail.
i try override of italian language:
jglobal_username="email"
jglobal_auth_invalid_pass="e-mail e password non coincidono o non hai ancora un account"

but no effects
how can that?

thank
frank

as may notice following result of search, text string "username" appears in more places other ones specified.

code: select all

search ""username"" (17 hits in 9 files)
  c:\wamp\www\joomla_36_4_lt\administrator\language\en-gb\en-gb.ini (1 hit)
   line 569: jglobal_username="username"
  c:\wamp\www\joomla_36_4_lt\language\en-gb\en-gb.com_users.ini (4 hits)
   line 37: com_users_field_reset_confirm_username_label="username"
   line 49: com_users_login_username_label="username"
   line 95: com_users_profile_username_label="username"
   line 114: com_users_register_username_label="username"
  c:\wamp\www\joomla_36_4_lt\language\en-gb\en-gb.ini (1 hit)
   line 262: jglobal_username="username"
  c:\wamp\www\joomla_36_4_lt\language\en-gb\en-gb.mod_login.ini (1 hit)
   line 31: mod_login_value_username="username"

suggest looking appropriate language strings in files mentioned.