Function nouns are a quick easy way to specify gender.  "r" ending is a thing or either gender. "m" is female.  "t" is male.

Pure-function nouns end with hyphnette + or.  The "-or" suffix is neutral:  it could be either gender or a thing.
        Form: verb-root + hyphnette + or, to which we can add "m" to designate female or "t" to designate male.
        A pure-function noun is "one who or that which verb-root.  Pure function words isolate the root-verb.
        E.g., a farm۔or is "one who farms", could be either gender or a thing.  A farm۔orm is a female farmer, farm۔ort a male.
        A  "toast۔or" is "that which toasts"，an example of a genderless function-noun

Regular-function-nouns also end in "or" (neutral), "orm" (female), or "ort (male), but without the hyphenette.
       E.g. a "carpentor" is not "one who carpents", so it is not a pure-function-noun.  Therefore no hyphenette.
       Yet we can still specify gender.  "Carpentorms" are female carpenters.
       There is no verb-root to isolate.

Passive-function-nouns describe "one who or that which was passive-mode-verb".    
        Form:  verb-root + hyphnette + eer, to which we can add "m" to designate female or "t" to designate male.
        E.g. an "adopt۔eer" is "one who was adopted.  An "adopt۔eerm" is a female who was adopted, "adopt۔eert" a male.
        Like pure-function-nouns, passive-function-nouns nicely isolate the verb-root, whose spelling never changes.

The lists below are samples of function-nouns.