I have discovered, in my studying of languages with gender cases, that words that end in the sound structure -tion, -cion -ție all seem to be feminine. Is this true for all languages with gender cases? If so, why? And if not, can you give me an example where the case is not feminine?
It’s true in:
French (nouns in -tion, -sion, -xion and -aison are nearly all feminine - the only exception I can think of is le bastion; edit: also the scientific term for a positively-charged ion, le cation)
Spanish (I can’t think of any exceptions to -ción being feminine - indeed, most -ión nouns are feminine with some rare exceptions including, of course, el bastión)
Portuguese (-tion becomes -ção, which is nearly always a feminine ending despite it ending in -o, a notable exception being o coração = heart)
German (though most German words in -tion come from feminine nouns in Romance languages - in this case, even die Bastion follows the rule and most -ion nouns are feminine too, with der Spion = spy an exception)
Polish (where -tion becomes -cja, which follows the general rule that nearly all -a nouns are feminine - I’m not aware of any exceptions but that doesn’t mean there aren’t any!)
As to the million dollar question of why these nouns are nearly always feminine, I’m not sure - presumably they have their origins in Latin and if so, a Latin scholar might be able to provide an explanation.
Words that end in -tion, -cion and -ţie are derived from Latin words that end in -tio and are feminine, e.g. sensatio -> sensation, sensación, senzaţie. https://en.wiktionary.org/wiki/sensatio#Latin
In German there are certain word endings that indicate the gender. Some are derived from Latin or Greek and some are just German but their equivalents are feminine too in other European languages, e.g. die Wahrheit -> la vérité, la verdad. If you see -heit in German, -ité in French and -dad in Spanish then the word is feminine.