Cxi tiuj amikoj promenos, these friends will take a walk.

61. The words "tiu" and "cxi tiu" may be used to distinguish between
persons or things "previously" mentioned and "just" mentioned:

Gertrude kaj Mario estas en la parko.
Tiu rigardas la florojn, cxi tiu kolektas ilin.

Gertrude and Mary are in the park.
The former (that one) looks at the flowers,
the latter (this one) gathers them.


POSSESSIVE FORM OF THE DEMONSTRATIVE PRONOUN.

62. To express possession, the demonstrative pronouns "tiu" and "cxi
tiu" have the special possessive or genitive forms "ties", that one's,
and "cxi ties", this one's. The use of "ties" and "cxi ties" to mean
"the former" and "the latter" is similar to the use of "tiu" and "cxi
tiu" shown in 61:


Mi iris al ties domo, I went to that one's house.
Cxi ties filoj estas junaj,
this person's (this one's) sons are young.
Mi sxatas ties koloron, sed preferas cxi tiun floron,
I like that one's color, but prefer this flower.
La patro kaj lia amiko parolas pri siaj domoj.
Ties estas nova, sed cxi ties sxajnas bela.
Father and his friend are talking about their houses.