For example, in Japanese, (i) we can insert indeterminate expressions in the proposition, (ii) we can use disjunction to express indeterminacy of the truth of propositions as shown in (8a) and (8b), and (iii) we can use the disjunctive particle "ka" as sentence-final question marker to express indeterminacy of the truth of P, as shown in (8c).
we assume that question is essentially partitioning, which is expressed as disjunction in Japanese.