Every word has its proper schwa which is produced through the mouth by the appropriately posed or positioned chin, tongue, and neck. This proper unaccentuated vowel or syllable for the certain languages is named as Juhn's anatomical schwa. In learning 2nd languages it can be very useful and much linguistic to teach how to voice the proper schwa. In linguistics the proper schwa has been expressed by International phonetic alphabet or phonography for a long time but Juhn's anatomical schwa is defined that the unaccentuated vowel or syllable is produced by the appropriately posed or positioned chin, tongue, and neck. After birth the child grows and develops the skull to the end and the baby teeth are lost to develop the permanent teeth and the jaw joints are to be firm gradually before the age of 7. For the 7 years the child learns the mother tongue so that his facial appearance becomes alike to his tribe who speaks the same language. The chewing and swallowing is alike with each other. The jaw joints become also firm to speak mother tongue easily. Thereafter the child can voice other language schwa not enough to speak it spontaneously. This is the first idea of the Juhn's locked chin. So we can postulate that the locked chin is made to be the jaw joints as soft as those the children under the age of 7 have for L2. This is the Juhn's unlocking rule and the solution for the Juhn's locked chin. Then we can move our chin and tongue to the next step producing the schwa for the second language.