... In the Tamil I speak we are generally very respectful (I was told it is Brahmin Tamil), I am not used to hearing Anda, andi, poda, podi etc. even in intimate circle.
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dear ada and adi...can be used as a term of endearment, but only in very intimate circle - spouse, siblings or close friends. i said 'can be' only because it is a mutual thing, and the other person too does the same.
re brahmin tamil, within the community we are ok, but are known for disrespect right from our servants to everyone else. even mrs K, i have to tell her, to address maids and auto rickshaw drivers as neenga vaanga ponga..and not nee vaa po.
p.s. krishnan, has noted in iyengar families of tamil nadu (and iyers too i would imagine) an eight year old, will address the servant by first name - amavasai! kuppai!..and such. it took periyar to dispel this habit, among this generation, and provide dignity of address.
we had a handy boy...we always addressed him as 'gundu paiyyan'. i never knew his real name.

as a rule, i have seen NBs in madras, address servants as anney or akka...as a rule that is. we would never address our maids as akka. even now.