I feel like my biggest things i missed in the [minimal] toki pona vocabulary are words for softness, decietfulness, spikyness, or categories, but with experience the gaps seem to shrink.
powe is a common nimi sin that has a distinct meaning from “lon ala”, but i prefer saying it like “sitelen taso” or “toki taso”. We all know that speech and symbols refer to things, but the word taso magically gets rid of the implied referent, and people understand that talk on its own is less powerful than talk should be.
A difficult concept to describe in any language is categories, groupings, species, *genera/genre/gender*, and “kinds”. There is a nimi pini for “kani”, and , but i think the metaphorical use of the word kule is really good for this. “kule mije meli” becomes a great way for me to express “that quality pertaining to male and female” aka “gender”, but i dont have enough conversation experience to know if it’s easy to understand in practice, let alone extend this use to talk about kinds of problems, animals, games, and so on.
For softness, once i started talking to experienced speakers i was suprised how readily the word “ko” which i thought would primarily sound like “powder” or “slime”, instead, in context, readily connotates “softness”, “body fat”, or “comfortable”, especially when modified with value judgements like “pona” or “suwi”. I have a friend or two who love the word “puwa” and i use it with them, but it’s awesome that i don’t even need it.
I feel like the least comfy thing here is spikyness. When i say “o lukin e kasi ni, ona li tan ma seli li wile e telo lili, nena ona li ken utala e selo!” It mases sense that “xerophyte” is a word that tokiponizes into complete sentences, but it feels cumbersome that “spiky” is treated just as abstract by toki pona. Would you understand me if you were in a desert and i said “kasi utala”?