[LAC-Tech]

does russian gender anything like prepositions or demonstrative? anything would help I think.

[grishka]

Prepositions don't change based on gender but make the word itself change case (обсуждение -> в обсуждении). The pronouns though, those are gender-specific (он/она/оно, этот/эта/это), regardless of whether they refer to people or not.