If the formal and informal ‘you’ forms of some languages seem like a minefield to the English speaker, Dyirbal, an Australian language from North Queensland extinct since about 1930, offers a challenge of another level yet.
Dyirbal comprised two separate sublanguages, each depending on who was present. A Dyalnuy, or “mother-in-law language”, was used in the presence of certain “taboo” relatives and a Guwal, or everyday language, was used in all other circumstances. Taboo relatives (parents- or children-in-law or a cross-cousins – i.e. a father’s sister’s or mother’s brother’s child – of the opposite sex) could not be approached or looked at, let alone spoken to directly. In the case of cross-cousins, the distinction was made so as to create a distance between people who might be interested in each other as spouses, which was forbidden. Thus the language signalled very clearly who was sexually available to whom.
While this may sound like a linguistic and cultural nightmare, the complexity of the social conventions and the key role that language plays are no less fascinating.