In Hindi, as in many other Indian languages such as Tamil, we use unique words to differentiate between relatives on our mother's and father's side of the family. The word "मामा" is a good example. Coincidentally, "mama" is also the word for "mother's brother" in Tamil.
अंग्रेज़ी (English): uncle, mother's brother, en:uncle
फ्रांसीसी (French): oncle, frère de la mère, पु. fr:oncle
Why is "Peter's uncle did come home" incorrect? I read somewhere online that the conjugation of someone who "had done" something was different
with हैं at the end it's the Present Perfect tense http://www.learning-hindi.com/post/5457387996/lesson-110-the-present-perfect-tense