Pin Yin Rules

Pin Yin Rule 1:

i上标调，要把点去。
"i" shànɡ biāo diào, yào bǎ diǎn qù.
If mark tones on the letter "i", please omit the dot.
Eg: 
d-i-dī -dí-dǐ-dì

Pin Yin Rule 2:

小ü碰到j, q, x, 去掉两点还念ü。
xiǎo "ü"  pènɡ dào j, q, x,  qù diào liǎnɡ diǎn hái niàn "ü".
If ü is put together with j, q, x, omit two dots but still read ü.
xiǎo ü  pènɡ dào j, q, x,  qù diào liǎnɡ diǎn hái niàn ü.
Eg:
 j-ü (u)-jū-jú-jǔ-jù
q-ü (u)-qǔ-qú-qǔ-qù 
x-ü (u)-xū-xú-xǔ-xù 

Pin Yin Rule 3:

开头发音是i/u, 前面加或改y/w。
kāi tóu fā yīn shì i/u,  qián miɑn jiā huò ɡǎi y/w.
If i/u appear at the beginning, please add y/w before it or change i/u into y/w.
Eg:
i-yī-yí-yǐ-yì (add y before i)
u-wū-wú-wǔ-wù (add w before u)
牙-iá-yá (change i into y)
娃-uá-wá (change u into w)

Pin Yin Rule 4:

开头发音是小ü，去掉两点加上y。
kāi tóu fɑ yīn shì xiǎo "ü", qù diào liǎnɡ diǎn jiā shànɡ "y".
If "ü" appears at the beginning, please omit two dots of "ü" and add "y" before it.
Eg:
ü-yū-yú-yǔ-yù 
月-üè-yuè

Pin Yin Rule 5:

有a在，把帽戴；a不在，o，e戴。
要是i，u一起来，谁在后面谁来戴。
yǒu "a" zài, bǎ mào dài; "a" bú zài, "o, e" dài,
yào shì "i , u" yì qǐ lái, shuí zài hòu miɑn shuí lái dài. 
If there is "a" in pinyin, the tone should be marked on "a",
If there is no "a", the tones should be marked on "o" or "e".
If "i" and "u" appear in pinyin at the same time, the tone needs
marked on the letter that appeared later.
Eg:
爱 (ài)，猫 (māo)
头 (tóu)，飞 (fēi)
六 (liù )，回 (huí )