Constructionalized rhetorical questions from negatively biased to negation polarity

How does a rhetorical question become an adverbial npi down-toner? This paper focusses on a specific type of grammaticalization process: the grammaticalization of a rhetorical construction à la Goldberg (1995), namely, a “constructionalized rhetorical question” (Bardenstein 2018) which turns into a down-toning adverbial. The particular focus of this paper is on the Hebrew lo mi yodea ma ('not who knows what'; i.e., 'not of high quality/quantity') which has developed from the constructionalization of two earlier constructions. Initially, the biblical question-phrase mi yodea ('who knows') constructionalized as “negatively biased” (Ladusaw 1996). This is a rhetorical question, to which the obvious answer is negative, and in our case mi yodea can be interpreted as 'nobody knows'. Most often, it is the case of “not knowing” what the future holds. Then, once a direct object ma ('what') was added, it constructionalized once again into a strengthening/intensification construction mi yodea ma ('who knows what'), conveying high quantity/quality. This happened since “not knowing what is to happen” can be interpreted as “anything can happen” and this interpretation was used rhetorically to strengthen one's utterance. Lastly, mi yodea ma ('who knows what') constructionalized under the scope of the negation operator lo ('not'), into a versatile down-toning adverbial: lo mi yodea ma. Since it is very difficult to negate a strongly positive construction without implying that a less positive one is to some extent true, this negated construction became a versatile down-toner.