Vocative Capitalization.

On another net forum, it occurred to me that, for those languages with
a vocative case, those nouns which would be in the vocative case would
be, in translation, considered to be English proper nouns -- i.e.,
capitalized nouns.

It does explain the really hard cases. "Why, Mother, are you ...",
"why, Mr. Congressman, have you told lies about Chandra".

I usually explain the difficult capitalization cases as 'titles'
standing in for real names.

This suggests English might actually have a remnant of a vocative
case. I don't think so, but it is an interesting topic to talk about.