Postulation the first: Cardassians with tails.
Postulation the second: Cardassians with second tongue (body language to emphasize/affect the meaning of words as an essential part of the language), and the tail being part of this second tongue.
Postulation the third: sure, you can use a universal translator for Kardasi if you don’t have a tail, but it always sounds a bit off; if you really want to speak the language…
Postulation the fourth: Julian Bashir, being fitted for his prosthetic tail.
A prosthetic tail would be interesting, but could also run the risk of malfunctioning, so…postulation: Julian gets shocked/pinched regularly by his tail and has to explain to Garak why he’s got bruises on his butt.
Alternative to the prosthetic tail: Humans use their hands to talk a lot in general anyway, so maybe a human ends up using one hand to imitate the tail movements of second-tongue while they’re speaking.
Solid gold post.
