Tap and Flap (was: Notes on UPSID phoneme inventory)

Pablo Flores asked:

> What's the difference between a tap and a flap? I thought
> they were the same!
Somewhat belated reply, but anyway...=20
AFAIK no one else answered.

I had the same question some months ago,
so I asked my teacher. He said that a tap
is when you very quickly "tap" the tip of your
tongue once against the alveoli. A flap is made
by "flapping" the underside of the tip of your
tongue against the back of the alveoli, kind of
the same way you'd make a retroflex IIUC.
When I do that it sounds like something=20
between /d/ and /l/, but that's what he said.

Hope my answer wasn't too confusing.
It's hard to explain when I can't use my
hand as a "tongue".

Daniel Andreasson