In "talossani", there's clearly two suffixes after "talo": -ssa is the suffix that marks the case -ni is the first person possessive suffix (not a case) The

In "talossani", there's clearly two suffixes after "talo": -ssa is the suffix that marks the case -ni is the first person possessive suffix (not a case) The first person singular pronoun would be "minä" and its genitive case "minun" - not a suffix but including the suffix -n that marks the genitive case. My house => Minun taloni (the possessive is visible in both words in formal Finnish: the genitive case in the pronoun, the possessive suffix in the noun) My house => Mun talo (less formal Finnish shortens the pronoun and does not use the possessive suffix) The fact that the possessive suffix is not a case does in no way indicate that there wouldn't be actual cases in Finnish. https://en.wikipedia.org/wiki/Finnish_noun_cases https://en.wikipedia.org/wiki/Finnish_noun_cases