A language with remnants of a defunct dual number can have many interesting peculiarities - consider, for instance, the case of Russian, where nominative numbers from two to four take singular genitive nouns - because historically, the nominative dual was identical to the singular genitive. However, even today, some exceptional nouns exist with an exceptional form in this context.
However, what if the duals leave different types of traces? Let's consider a language where the dual has been thoroughly present - in verb morphology, in pronouns, etc - but since the society has become more complex and bigger numbers have become commonplace, the dual has mainly fallen out of use. However, it survives in a few contexts:
- things that often come in pairs
- socially pairwise things
However, it also survives in certain participles and verbs with a variety of unexpected meanings:
- With some applicative participles, formerly signifying the use of both hands for carrying out the action, now signifying intensity and without the applicative meaning preserved.
- With applicative participles of verbs of perception, the dual signifies 'with the ears' or 'with the eyes' and thus basically just serves to enhance the fact that the speaker has seen or heard what he's speaking of.
- With some active participles that formerly just signified pairs doing something, now the dual marker signifies reciprocality within socially important structures of two.
- With some gerunds a dual morpheme indicates repetition, whereas plural marks habituality.
Also, as a side note: yay, definitely 100k views in total, although no idea to what extent those are bots.