Second day on the same lesson — p.3, word building, one sound swapped at a time. Do not re-teach it. Re-run the column and go at whatever the children were not accurate on yesterday.
Put the tip of your tongue on the bumpy ridge just behind your top teeth. Hold the air. Now let it go — /t/. Voice off.
They check it: Hand in front of your mouth — a small puff. Hand on your throat — still.
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.