Instead of `it` for one, and `this` and `that` for two, use `este`, `ese` and `aquel` for three (from the 3-tier pronoun system in Spanish).

Please don't ask what if there's four. Very few (if any) natural languages have more than 3 tiers of demontrative pronouns, so computer languages shouldn't -- if they're using ideas natural language to be more readable. They would use identifiers or numeric subscripts instead.