If you enable a new language in your Oracle installation, use WFNLADD.sql to add the missing rows for that language to the Oracle Workflow translation tables. See: Setting Up Additional Languages and wfnlena.sql.
Use the script as follows:
sqlplus <user> @WFNLADD Enter password: <password>
Note: The wfnlena.sql and WFNLADD.sql scripts prepare the database for loading workflow definitions in another language. However, these scripts by themselves do not enable displaying Oracle Workflow Web pages in other languages. See: Setting Up Additional Languages.