In the Bangla language, we have some additional words that don't exist in English. For example, in English, we call him uncle. In Bangla, we have chacha (father's brother), fufa (father's sister's husband), mama (mother's brother), khalu (mother's sister's husband), taloi (sister's father-in-law), etc. If we translate these into English, all of them would be called uncle.
In my childhood, I was very confused about all these relationships. So, sometimes I used to follow what my mother says. For example, I used to call Dula bhai (brother-in-law) to my Boro Khalu (uncle). Later, I figured out that my mother called him Dula bhai. One day, my older sister corrected me. I tried to remember that, but sometimes, by mistake, I used to call him Dula bhai.