Vowel Shortening
-iou, -uei, -uen become -iu, -ui, -un
When preceded by an initial, the sound clusters /iou/, /uei/, and /uen/ are written as {iu}, {ui}, and {un}, respectively.
| Actual Sound | Pinyin Form |
|---|---|
| -iou becomes -iu (no exceptions) |
|
| miou | miu |
| diou | diu |
| niou | niu |
| liou | liu |
| jiou | jiu |
| qiou | qiu |
| xiou | xiu |
| xiou | xiu |
| -uei becomes -ui (no exceptions) |
|
| duei | dui |
| tuei | tui |
| guei | gui |
| kuei | kui |
| huei | hui |
| zhuei | zhui |
| chuei | chui |
| shuei | shui |
| ruei | rui |
| zuei | zui |
| cuei | cui |
| suei | sui |
| -uen becomes -un (no exceptions) |
|
| duen | dun |
| tuen | tun |
| guen | gun |
| kuen | kun |
| huen | hun |
| zhuen | zhun |
| chuen | chun |
| shuen | shun |
| ruen | run |
| zuen | zun |
| cuen | cun |
| suen | sun |
-buo, -puo, -muo, -fuo become -bo, -po, -mo, -fo
When preceded by an initial, the sound clusters /buo/, /puo/, /muo/, and /fuo/ are written as {bo}, {po}, {mo}, and {fo}, respectively.
| Actual Sound | Pinyin Form |
|---|---|
| For b- p- m- f- -uo becomes -u |
|
| buo | bo |
| puo | po |
| muo | mo |
| The rest of the -uo syllables do not change: | |
| duo | duo |
| tuo | tuo |
| nuo | nuo |
| luo | luo |
| guo | guo |
| kuo | kuo |
| huo | huo |
| zhuo | zhuo |
| chuo | chuo |
| shuo | shuo |
| ruo | ruo |
| zuo | zuo |
| cuo | cuo |
| suo | suo |
Syllabification
You may be thinking that some of these spelling rules are really crazy. Why did the creators of Pinyin decide to make all of these exceptions? In many case, these irregularities were created to decrease ambiguity in the Pinyin spelling of multisyllabic words. For example the word {jiuwo} (if written without tones) only has one possible break down of syllables: jiu-wo. If the rules above did not exist and it was written with the actual sounds in Romanization: jiouuo it could be interpreted in any one of the following ways: jiou-u-o, jiou-uo, ji-ou-u-o, ji-ou-uo, ji-o-u-u-o, or ji-o-u-uo.