The 'j' descender is one of the trickiest shapes for young hands. Many children stop the line at the baseline because that is where they have always stopped. Tell them this letter goes underground, like a root. Practise 'j' next to 'g' and 'y' so the child sees that all three letters share a tail that goes below the line. The dot is always added at the end, never at the start.

Some letters stay on the line. 'j' goes deeper. Be brave with your tail. Letters that risk the descent are the ones the eye remembers.