2. After the initial mastery, put the back of your hand close to the teacher's throat, let him feel the vibration of the vocal cords and learn to pronounce the vowel "er".
3, after being able to skillfully become warped, practice repeatedly in front of the mirror. Learn to hold your tongue against the hard palate, and then practice pronouncing zh, ch, sh, R, zh, ch, sh, R, er, all of which are rolled tongue sounds.
4. Use your thumb to cling to the back of your upper teeth and gums, with your nails facing the inside of your mouth, and practice pronouncing zh, ch, sh and ro. If the thumb nail is not wet when pronouncing, it proves that you can pronounce "hard palate sound".
5. After a period of time, do the following exercises in combination with er sounds: ER-CH; ; er-zh； er-sh； er-r； After proficiency, remove er until zh, ch, sh and R are issued independently and correctly.