When nasal -N is pronounced, the tip of the tongue is pressed against the upper gum to avoid loosening or retraction; When the nasal sound is -ng, the root of the tongue is raised high, and the root of the tongue is retracted against the soft palate as far as possible. 2. Different mouth shapes
When the hair is -n, the upper and lower incisors are opposite and the mouth shape is closed; When the hair is -ng, the upper and lower incisors are far apart and the mouth shape is wide. 3. Different timbres
The anterior nasal sound -n is sharp and clear, and the posterior nasal sound -ng is rich and loud.