It was noted in 1.2.1 that, in many languages, particularly the Native American languages and those of Papua New Guinea, mood is described in terms of the grammatical markers of realis and irrealis. Although the distinction is basically the same as that between indicative and subjunctive, both being markers of the typological categories Realis and Irrealis, there are sufficient differences to warrant discussion of them in a separate chapter. Yet there is not always a clear distinction between them – see 7.1 for discussion.

Joint and non-joint marking

There are basically two ways in which realis and irrealis markers function. In some languages their main function is to co-occur with other grammatical categories. In others they mainly occur in isolation and are themselves the only markers of specific notional categories.

For instance, in Amele (Papuan – Roberts 1994: 372) an irrealis marker is required whenever a future marker is present in the sentence:

By contrast in another Papuan language, Muyuw (Bugenhagen 1994: 18, quoting a personal communication), the irrealis marker is itself the indication of future:

Strictly, these might seem not to be comparable in that, in the Amele example, there is a syntactic relationship between two grammatical markers, irrealis and future, whereas in the Muyuw example there is simply a specific grammatical marker, irrealis, that indicates futurity.