Like most suffixes, -ary changes the grammar rather than the meaning. It usually changes a word from a noun or verb into an adjective, as in imagine/ imaginary or element/ elementary.
Quite often a word ending in -ary will be a noun, especially one describing a person with a specific role, eg functionary, dignitary. These nouns originally derived from adjectives.
Quite often a word ending in -ary will be a noun, especially one describing a person with a specific role, eg functionary, dignitary. These nouns originally derived from adjectives.