Per p 24, A Student's Introduction to English Grammar (2005), by Huddleston & Pullum,
Polarity is the name of the system contrasting positive and negative clauses.
I ask this question in general, and NOT only for English. Negativity still incapicitate my reading comprehension, but one recourse is to rewrite negative clauses into positive clauses. For example, these equivalences helped me to parse the negative clauses:
cannot ... anything = can ... nothing, and not without = only with or only by.
I wish to learn more and be exposed to more such rewrites. So what's this kind of syntactical rewrite or substitution called? Are there any practice books or guides?
Are there any lists or catalogues of such equivalences, for my reference?