We can categorize the pronouns in Turkish in seven:

a) personal pronouns

b) posessive pronouns

c) indefinitive pronouns

d) questional pronouns

e) reflexive pronouns

f) demonstrative pronouns

g) "-ki" which is pronoun

Let´s start.

A) PERSONAL PRONOUNS

Our language has six personal pronouns. Let´s remember them.

All of them have a special suffix except the third singular person "o". We call those suffixes "personal suffix". The meaning stays the same even if the personal pronouns aren´t used because the personal suffixes already expresses the meaning. But you have to always use the personal suffixes. The task of the personal suffixes is to make the word predicate. Don´t forget this!

Let´s see different things.

For example, you are looking at a photo. You ask to me:

-Bu kim? (Who is this?)

-Benim. (He is me.) (direct: He is I)

-Bu sen misin? (Is this you?)

-Hayır, ben değilim. (No, he´s not me)

etc.

B) POSESSIVE PRONOUNS

Let´s remember them, too.

C) "-Kİ"

kalem (the pencil)

mavi (blue)

mavi değil (not blue)

-Bu kalem senin mi? (Is this yours?)

-Hayır, benim değil. (No, it´s not mine.) (direct: it´s not my)

If you take care... I didn´t write "seninki mi?", "benimki değil". The meaning doesn´t change even if I write so. But we use the posessive pronouns directly. We use this type almost everytime.

bahçe (the garden)

geniş (large)

bizim bahçemiz (our garden)

=bizimki (ours/ours one)

Sizin bahçeniz geniş. Bizimki geniş değil. (Your garden is large. Ours one isn´t large.)

onun oyuncakları (his toys)

=onunkiler (his ones)

Onunkiler daha iyi. (His ones are better)

The "-ler" is normal plural suffix that you had learnt. There is no special situation. Its structure is "onunki+ler" like the structure of "okullar (schools)" is "okul+lar".

sizin çocuğunuz (your child)

=sizinki (yours/your one)

Sizinki okuldan döndü mü? (Has yours come back from the school?)