Is there any known natural language in which it is possible to express grammatically—i.e., not through emotional tone or other secondary traits—multiple parallel channels of meaning? Parallel structures could be made explicit in such a language by simultaneous articulation.
Consider a hypothetical language in which words can overlap:
- [ʔņ] = “have, there is”
- [po] = “apple tree”
- [ka] = “rain”
- [k͡pʼœ̃] = “it is raining and there is an apple tree”.
(In which [p] and [k] become coarticulated, [ʔ] becomes ejective colouring, [o] and [a] combine to form [œ], and the syllabic [ņ] nasalises the vowel.)
The process is essentially synthesis with a pathologically high degree of sound change.
Naturally this is a contrived example, and a phonologically unusual one; I’d expect a language that has anything remotely resembling this to have some provisions for keeping things manageable.
This doesn’t seem outside the realm of possibility, and in my experience with conlangs, I’ve learned not to be surprised when natural languages turn out to be far weirder and more wonderful than anything an individual can come up with.