p.5 — word building, one sound swapped at a time. 8 words and 1 sentences, 28.4 minutes.
Tongue tip on the ridge behind your top teeth, same as /t/. Voice ON — /d/.
They check it: Hand on your throat: /d/ buzzes, /t/ does not.
Not in Urdu. For those children this is a new physical skill, not a reminder. Do not let the column start until the mouth can make it.