Olha,
I hope you already found a solution, but if not I think I can help.
To delete the mistakenly created Language version of an object you have to run the same report mentioned in above comments i.e.
From Easy Access follow the path below:
Human Resources > Organizational Management > > Tools > Infotype > RE_RHTRANS0 - Translate
Once you put necessary details in the selection screen and run the report, you can select the incorrect record and press the delete button and then press save button. This will delete the incorrect language entry.
You can check all the languages maintained for an object in table hrp1000.