In some cases we have two unique (continuous) morphemes which always occur together, though not next each other. In Yokuts, whenever 'na’aṣ' occurs, a verb with the suffix '–al' occurs with it; and whenever the verb-suffix '–al' occurs, 'na’aṣ' occurs nearby. Together, they indicate uncertainty of the action; it would presumably be impossible to give the descriptive meaning of each one of them, since they never occur separately: 'hina’ ma’ na’aṣ xat-al' ‘Perhaps you might eat’, 'tunac na’aṣ so:g-al' ‘(He) might pull out the cork’, 'xatxat-al na’aṣ' ‘(He) might eat repeatedly’. Instead of saying that we have here two morphemes which always occur with each other, we can say that we have just one morpheme whose phonemes are not consecutive: 'na’aṣ … -al' (with the rarer variant '–al … na’aṣ'). We thus obviate the need for a restrictive statement about the two continuous morphemes. Such simple discontinuous morphemes are infrequent.
- Harris (1945a), a pag.122