Pronounce it really fast. Try pronouncing "water" really fast while you're at it.

North Americans flap their t's - making them sound like d's. The difference between a T and a D is the use of your vocal chords- you use them for the D and you don't for the T. It's the same for P's and B's.

We (North American's) tend to alter our 't' sounds in many ways - how many people do you know who pronounce "kitten" or "button" with both t's? most of us say "ki-en" or "bu-un".

The Brits do it with their A's (So do East Coastnerners in the US) and Aisans tend to mix up their L and Rs (the liquids)

Nat