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N.B. The sex of the 3rd person is expressed by different words, not by suffixoid in (amikino – she-friend) or prefixoid vir (virkato – tom cat) as with nouns.
Like English, Esperanto uses the same pronoun in the 2nd person for both numbers. If it is necessary to distinguish formal and informal addressing, it is possible to the pronoun ci (thou, fra: tu, deu: du) for the informal singular, so-called cidiri
There is also reflexive pronoun si. Si is used instead of the normal 3rd person pronouns (li, ŝi, ĝi, ili) when referring to the subject of the sentence:
Paŭlo lavas sin. – Paul washes himself.
Paŭlo lavas lin. – Paul washes him. (It means someone else).
Ili lavas sin. – They wash themselves.
The reflexive pronoun is not used for the 1st and 2nd person (Mi lavas min. – I wash myself). Si can form accusative but nominative can be used only as a prepositive nominative.
General subject is expressed by the pronoun oni. Oni is vague and can stand for one or more persons – predicative can be in singular (Oni devas ĉiam esti preta.M – It is necessary to be ready all the time.) or in plural (Oni estas maljustaj koncerne ilin.M – People are not fair to them.). Singular is preferred. The form onin is possible, but not used.
The pronoun ĝi should be used also when referring to a human without specifying its sex. Some Esperanto speakers have proposed a new pronoun ri, reserving ĝi for things and non-human beings. However, ri is used very rarely. Other forms (liŝi, ŝili and ŝli) were proposed too, but they are even more rare. Some other Esperanto speakers would like to have pronoun for female 3rd person plural – plural of ŝi – they have proposed iŝi (as analogy to the pair li – ili). This pronoun is also used only rarely.
Possessive pronouns are formed from the personal pronouns by adding the adjectival ending a. Possessive pronouns are declined as adjectives. The pronoun has to agree in number and case with the thing(s) that are possessed.
mia domo – my house
miaj domoj – my houses
Mi vidas mian domon. – I see my house.
Mi vidas miajn domojn. – I see my houses.
Li vidas sian domon. – He sees his own house. (The house belongs to the person who sees it.)
Li vidas lian domon. – He sees his house. (The house belongs to some other person.)
It also is possible to form possessive form of oni – onia, but I cannot find any interpretation for it.
 There is also a prefix sin which is synonymous to the prefix mem (self, own). However, it is better to look at it as a separate prefix and not as the reflexive pronoun: (1) if it were the reflexive, it would be in nominative – the accusative form is used only because of the easier pronunciation; (2) it is used also for the first and second person, in which case the form mi, ni or vi should be used.