| Relation | Hindi | His wife |
|---|---|---|
| Father's elder brother | ताऊ taau | ताई taai |
| Father's younger brother | चाचा chacha | चाची chachi |
| Mother's brother | मामा mama | मामी mami |
| Father's sister's husband | फूफा foofa | बुआ bua |
| Mother's sister's husband | मौसा mausa | मौसी mausi |
दादा/दादी on the father's side, नाना/नानी on the mother's. Saying "I'm going to my nani's house" tells any Hindi speaker immediately that you mean your mother's mother.
In a joint family the relationship determined who you lived with, who could correct you, and how property passed. Precise words were necessary, and they stayed.
The practical effect today: calling everyone "uncle" is understood but marks you as an outsider. Getting chacha versus mama right marks you as someone who knows the family.
Every relation, including the in-laws, is listed in our guide to Hindi family words.
Reading an answer is one thing; being corrected while you say it is another. EkGuru tutors teach one to one from $6 a lesson, and most offer a trial.