these are the common use words in our regular basis.

family members and relations

meaning: Mother, Mom
This is how we call our mother in Sinhala

Meaning: Father, Dad
This is how we call our father in Sinhala

Brother (Big brother or Elder brother / Little brother or younger brother )

It's common to call Ayya, our elder brother, and Malli, our younger brother.

සහෝදරයා ( අයියා / මල්ලි ) -  Sahodaraya ( Ayya / Malli )

Sister ( Big sister or Elder sister / little sister or younger sister)
It's common to call Akka, our elder sister, and Nangi, our younger sister.

සහෝදරිය ( අක්කා / නංගි ) - Sahodariya ( Akka / Nangi )

ආච්චි අම්මා  (Aachchi amma )

සීයා / ආතා   (Seeya / Aatha )

Aunt / Uncle  (Mostly, In Sinhala we call uncle and Aunt (Mama / Nenda) only for our father's Sisters and their spouses, our mother's brothers and their spouses, and also some elders out of our family)

නැන්දා / මාමා or නැන්දි / මාමි (Nenda / Mamaa or Nendi / Mami)

We call Bappa and Punchi for our father's younger brothers and their spouses, or our mother's younger sisters and their spouses.

බාප්පා (බාප්පි) / පුංචි අම්මා (පුංචි)  - Bappa (Bappi) / Punchi amma (Punchi)