"UNUS NAUTA" words ("-ius" gen. sing.and "-i" dat. sing.)

There are TEN common pronouns/adjectives, some already known to you, which show the same variant pattern in the GENITIVE and DATIVE SINGULAR as one finds in the relative (qui, quae, quod) and demonstrative (hic/ ille/iste) pronouns and intensive adjective (ipse). UNUS NAUTA is a mnemonic acronym.