The letter J is signed by holding up your dominant hand, palm facing out, with your fingers curled into a fist except your pinkie sticking out. Then make a 'J' in the air with your pinkie finger, starting from the top of the 'J' stem down and curving up again to form the bottom part of the letter. It is as if you are dipping your pinkie finger in a jar of jam!
Teach your toddler the letter J sign when it is necessary to finger-spell some simple words - or the initials of objects, places, animals, or people's names. That way, your toddler slowly begins to associate the sign with the sound of the letter in a word or name.
This is a useful flash card taught best in conjunction with the other letters of the alphabet.