A Complete Grammar of Esperanto (50)
LESSON L.
THE PRONOUNS ENDING IN "-O".
233. In contrast to the pronouns ending in "-u" ("tiu", "kiu", "chiu",
"iu", "neniu"), a similar series ending in "-o" refers to an object,
fact or action not definitely specified (but never to a person), like
English "what, anything, something, nothing," etc. Because of their
somewhat vague meaning, these pronouns do not occur in the plural, nor
are they ever used as pronominal adjectives:
Demonstrative: tio = that (thing, fact or action).
chi tio = this (thing, fact or action).
Interrogative and Relative: kio = what.
Distributive: chio = everything.
chio chi = all this.
Indefinite: io = anything, something.
Negative: nenio = nothing.
234. A pronoun (not personal) in predicate or relative relation to a
pronoun ending in "-o" must itself be of the same series:
Kio estas chi tio, kion vi diras? What is this, which you say?
Shi vidis tion, kio jhus okazis, she saw that which just occurred.
Chio chi, kion vi vidas, estas farita de ili,
everything here (all this), which you see, was done by them.
Li havas ion por vi, sed nenion por mi,
he has something for you, but nothing for me.
THE PRONOUNS ENDING IN "-O".
233. In contrast to the pronouns ending in "-u" ("tiu", "kiu", "chiu",
"iu", "neniu"), a similar series ending in "-o" refers to an object,
fact or action not definitely specified (but never to a person), like
English "what, anything, something, nothing," etc. Because of their
somewhat vague meaning, these pronouns do not occur in the plural, nor
are they ever used as pronominal adjectives:
Demonstrative: tio = that (thing, fact or action).
chi tio = this (thing, fact or action).
Interrogative and Relative: kio = what.
Distributive: chio = everything.
chio chi = all this.
Indefinite: io = anything, something.
Negative: nenio = nothing.
234. A pronoun (not personal) in predicate or relative relation to a
pronoun ending in "-o" must itself be of the same series:
Kio estas chi tio, kion vi diras? What is this, which you say?
Shi vidis tion, kio jhus okazis, she saw that which just occurred.
Chio chi, kion vi vidas, estas farita de ili,
everything here (all this), which you see, was done by them.
Li havas ion por vi, sed nenion por mi,
he has something for you, but nothing for me.