拼写规则 pīnxiě guīzé Rules of Spelling

1. if there is no initial in front of i, 
i

2. if there is no initial in front of u,
u

3. if there is no initial in front of ü, 
ü

4. When ü is with j, q, x, →
居 jū

5. When iou、uei、uen are with initials, →
iou →
uei