We can use two nouns to construct a new noun by attaching the possession suffix (s)İ to the second noun:

handbag	el çantası
backpack	sırt çantası
cellphone	cep telefonu
apple trees	elma ağaçları
ankle	ayak bileği
wrist	el bileği
toe	ayak parmağı

If we use possession suffixes in combination with compound nouns, the suffix of the compound noun disappears:

my handbag	el çantam
your backpack	sırt çantan
my father's cellphone	babamın cep telefonu
our apple trees	elma ağaçlarımız
Whose ankle?	Kimin ayak bileği?

In the word babamın the possession suffix m, denoting that it is my father, is followed by the genitive suffix ın indicating that he in turn possesses the phone.

Breakdown of ayak parmağı