be tongue-tied
have the gift of the gab
talk the hind legs off a donkey
Chinese whispers
you're not one to talk
talk nineteen to the dozen
put it in a nutshell
let the cat out of the back
eat (my) words
words fail (me)
word for word
hold (my) tongue
making a mountain out of a molehill
make heavy weather of ...
storm in a teacup
give a blow by blow account