Questions about example sentences with, and the definition and usage of "Less"

A: not very often

A: As he studied the more his knowledge grew

A: this is something even native speakers struggle with sometimes.
“fewer” is used for things you can count whereas “less” is used for singular things in terms of mass.
examples:
“fewer dollars” versus “less money”
or
“fewer ingredients” versus “less food”

A: It's the same meaning "bez", but some words like the suffix and some the "without"