T

Refer to the numbers on this diagram.

Normal T
16 + 4 and don't let the tongue touch the back of the top teeth.

Flapped T
'American-style', just one flap of 16 against 4.

Unreleased T
Start the normal T sound but don't finish it, i.e. don't let the air come out.

Unreleased dental T
Like unreleased T, but use 17 + 3 (edge of the teeth) so that you are in the correct position for the TH sound that comes next.