Examples of assertive words include "some, once, already, somebody, something, sometimes, somewhere, someone."
The source also explains that non-assertive words are used " in questions and negatives. They are also used in if-clauses and with adverbs, adjectives, verbs, prepositions and determiners that have a negative meaning."
Examples of non-assertive words include "any, anything, anybody, ever, & yet."
However, as I read the source, I wasn't able to determine exactly what the semantic or pragmatic difference between assertive and non-assertive words is. I'm hoping that someone can spell this out for me, and/or recommend a source that explains the difference.