If I understood right the Locative is mostly to be formed in singular (e.g. domi, ruri, ...). Some websites say that we just use the same form as the genitive, some websites say that we use the genitive in 1st and 2nd declension and the ablative in 3rd declension.
That fits if we look at humus (humi, genitive), bellum (belli, genitive) and also cities like Carthago (Carthagine / Carthagini, ablative).
But then I was confused as I found locatives like ruri (dative), tempori (dative) and luci (dative).
What about them?