POSSESSIVE FORM OF THE DEMONSTRATIVE PRONOUN.
62. To express possession, the demonstrative pronouns tiu and ĉi tiu have the special possessive or genitive forms ties, that one's, and ĉi ties, this one's. The use of ties and ĉi ties to mean "the former" and "the latter" is similar to the use of tiu and ĉi tiu shown in 61:
Mi iris al ties domo, I went to that one's house.
Ĉi ties filoj estas junaj, this person's (this one's) sons are young.
Mi ŝatas ties koloron, sed preferas ĉi 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 ĉi ties ŝajnas bela, Father and his friend are talking about their houses. The former's is new, but the latter's seems beautiful.
THE SUFFIX -IL-.
63. Names of instruments, tools or utensils may be formed by adding the suffix -il- (followed by the ending -o) to roots whose meaning permits:
flugilo, wing (from flugi, to fly).
kaptilo, snare, trap (from kapti, to catch).
kudrilo, needle (from kudri, to sew).
montrilo, indicator, (clock) hand (from montri, to point out, show).
tenilo, handle (from teni, to hold).
The root of a word is that part of it which contains the essential meaning, and to which the verb endings -i, -as, -is, -os, the noun ending -o, the adjective ending -a, etc., are attached, when no suffix intervenes. Thus, vir- is the root of viro and of virino; kur- is the root of kuri, etc.
THE EXPRESSION OF MEANS OR INSTRUMENTALITY.
64. The means or instrumentality through which an act is accomplished is expressed by use of the preposition per:
Oni kudras per kudrilo, one sews by means of (with) a needle.
La birdoj flugas per flugiloj, the birds fly by (with) wings.
Li amuzas sin per tiuj bildoj, he amuses himself with (by) those pictures.
Mi trovis ĝin per via helpo, I found it by (through) your help.