the translations of the pspp software are done via
https://translationproject.org/domain/pspp.html
Some translations are pretty old and in the meantime new features
have been added which are not translated yet. Below you see the
poedit software with the current russian translation. The last translated
russian version is for example from 2015 and therefore only 1652 of 2439
phrases are currently translated.
Spanish, Catalan, Ukrainian and German are up to date but other languages have not even been translated once - like Finnish for example. So check https://translationproject.org/domain/pspp.html and if you think you can help - contact the language team for your particular language and: Your are a translator!
Regards
Friedrich