205. Nouns may be formed from participles, by substituting the noun
ending "-o" for the adjectival ending "-a". Such participial nouns
indicate persons temporarily or non-professionally performing or
undergoing that which is expressed by the root:
helpanto, one who is helping, an assistant.
elpensinto, one who has thought out something, an inventor.
legonto, one who is about to read.
vidato, one (being) seen.
sendito, one (having been) sent, an envoy.
la jugxoto, the one about to be judged, the accused.
[Footnote: Participial nouns must not be confused with nouns formed
by the suffix "-ist-" (172) expressing professional or permanent
occupation: "rajdanto", a rider, "rajdisto", jockey, horseman,
"jugxanto", a judge (of something), "jugxisto", judge (professional),
"laboranto", a person working, "laboristo", laborer.]