Pinyin

Pīnyīn, more formally Hànyǔ pīnyīn, is the most common Standard Mandarin romanization system in use. Hànyǔ means the Chinese language[1], and pīnyīn means "spell".[2] Pīnyīn uses the Latin alphabet to represent sounds in Standard Mandarin. The way these letters represent sounds in Standard Mandarin does not correspond to any other one particular language that uses the Roman alphabet. For example, the sounds indicated in pīnyīn by b and g correspond more closely to the sounds indicated by p and k in some Western uses of the Latin script, e.g., French. Other letters, like j, q, x or zh, indicate sounds that do not correspond to any exact sound in English. Some of the transcriptions in pīnyīn, such as the ian ending, do not correspond to English pronunciations, either. This means that people who have not studied Chinese, or who have studied Chinese but not the pīnyīn system, are likely to severely mispronounce some words if they attempt to pronounce pīnyīn according to their own language spellings. However, this very disregard for conventional pronunciations of the letters has enabled pīnyīn to represent Chinese sounds with economy and internal consistency.

History
In 1954, the Ministry of Education of the PRC assigned a Committee (Committee for the Reform of the Chinese Written Language) to reform the written language. This committee developed Hànyǔ Pīnyīn based upon existing systems of that time (Gwoyeu Romatzyh of 1928, Latinxua Sin Wenz of 1931, it uses the diacritic markings from Zhùyīn)[3]. The main force behind pīnyīn was Zhōu Yǒuguāng (born 1905, turning
103 in 2008 in good health). [4] [5] Zhōu Yǒuguāng was working in a New York bank when he decided to return to China to help rebuild the country after the war. He became an economics professor in Shanghai. The government assigned him to help the development of a new romanisation system. The switch to language and writing largely saved him from the wrath of the Cultural Revolution of Máo Zédōng.
A first draft was published on February 12 1956. The first edition of Hànyǔ Pīnyīn was approved and adopted at the Fifth Session of the 1st National People's Congress on February 11, 1958. It was then introduced to primary schools as a way to teach Standard Mandarin pronunciation, and used to improve the literacy rate among adults. In 2001, the Chinese Government issued the National Common Language Law, providing a legal basis for applying pīnyīn.[6] Hànyǔ Pīnyīn superseded older romanization systems such as Wade-Giles (1859; modified 1892) and Chinese Postal Map Romanization, and replaced zhuyin as the method of Chinese phonetic instruction in mainland
China. Hànyǔ Pīnyīn was adopted in 1979 by the International Organization for Standardization (ISO) as the standard romanization for modern Chinese(ISO-7098:1991). It has also been accepted by the Government of Singapore, the Library of Congress, the American Library Association, and many other international institutions. It has also become a useful tool for entering Chinese language text into computers. Chinese speaking Standard Mandarin at home use pīnyīn to help children associate characters with spoken words which they already know; however, for the many Chinese who do not use Standard Mandarin at home, pīnyīn is used to teach them the Standard Mandarin pronunciation of words when they learn them in elementary school.
Pīnyīn vowels are pronounced similarly to vowels in Romance languages, and most consonants are similar to English. A pitfall for English-speaking novices is, however, the unusual pronunciation of x, q, j, c, zh, ch, sh and z (and sometimes -i) and the unvoiced pronunciation of d, b, and g. More information on the pronunciation of all pinyin letters in terms of English approximations is given further below.
The pronunciation of Chinese is generally given in terms of initials and finals, which represent the segmental phonemic portion of the language. Initials are initial consonants, while finals are all possible combinations of medials (semivowels coming before the vowel), the nucleus vowel, and coda (final vowel or consonant).

Conventional order (excluding w and y), derived from the Zhùyīn) system, is:
b p m f d t n l g k h j q x zh ch sh r z c s

Finals
In each cell below, the first line indicates IPA, the second indicates pīnyīn for a standalone (no-initial) form, and the third indicates pīnyīn for a combination with an initial. Other than finals modified by an -r, which are omitted, the following is an exhaustive table of all possible finals. 1 The only syllable-final consonants in standard Mandarin are -n and -ng, and -r which is attached as a
grammatical suffix. Chinese syllables ending with any other consonant is either from a non-Mandarin language (southern Chinese languages such as Cantonese, or minority languages of China), or it indicates the use of a non-pinyin Romanization system (where final consonants may be used to indicate tones).

Rules given in terms of English pronunciation
All rules given here in terms of English pronunciation are approximate, as several of these sounds do not correspond directly to sounds in English.

Pronunciation of initials
b [p] unaspirated p, as in spit
p [pʰ] aspirated p, as in pit
m [m] as in English mom
f [f] as in English fun
d [t] unaspirated t, as in stop
t [tʰ] aspirated t, as in top
n [n] as in English nit
l [l] as in English love
g [k] unaspirated k, as in skill
k [kʰ] aspirated k, as in kill
h [x] like the English h if followed by "a"; otherwise it is pronounced more roughly (not unlike the Scots ch)
j [tɕ] like q, but unaspirated. (To get this sound, first take the sound halfway between joke and check, and then slowly pass it backwards along the tongue until it is entirely clear of the tongue tip.) While this exact sound is not used in English, the closest match is the j in ajar, not the s in Asia; this means that "Beijing" is pronounced like "bay-jing", not like "beige-ing".
q [tɕʰ] like church; pass it backwards along the tongue until it is free of the tongue tip
x [ɕ] like sh, but take the sound and pass it backwards along the tongue until it is clear of the tongue tip; very similar to the final sound in German ich, and to huge or Hugh in some English dialects
zh [ʈʂ] ch with no aspiration (take the sound halfway between joke and church and curl it upwards); very similar to merger in American English, but not voiced
ch [ʈʂʰ] as in chin, but with the tongue curled upwards; very similar to nurture or tree in American English, but strongly aspirated
sh [ʂ] as in shinbone, but with the tongue curled upwards; very similar to undershirt in American English
r [ʐ] or [ɻ] similar to the English r in rank, but with the lips spread and with the tongue curled upwards
z [ts] unaspirated c (halfway between beds and bets) (more common example is suds)
c [tsʰ] like ts, aspirated (more common example is bats)
s [s] as in sun
w [w] or [u] may be considered as an initial or a final, and may be pronounced as w or u as in English
y [j] or [i] may be considered as an initial or a final, and may be pronounced as y or i as in English

Pronunciation of finals
The following is an exhaustive list of all finals in Standard Mandarin. Those ending with a final -r are listed at
the end.
To find a given final:
Remove the initial consonant. For zh-, ch-, sh-, both letters should be removed, they are single consonants spelt with two letters.
1. Although y- and w- are consonants nevertheless they may be considered as part of finals and do not remove those. Syllables beginning with y- and w- may be considered as standalone forms of finals "i, u, ü" and finals beginning with "i-, u-, ü-".
2. If a syllable begins with j-, q-, x-, or y-, and the final is -u or starts with -u-, then change -u or -u- to -ü or -ü-.

Orthography

Letters
Pīnyīn differs from other romanizations in several aspects, such as the following:
Syllables starting with u are written as w in place of u (e.g. ueng is written as weng). Standalone u is written as wu.
Syllables starting with i are written as y in place of i (e.g. iou is written as you). Standalone i is written as yi.
Syllables starting with ü are written as yu in place of ü (e.g. üe is written as yue).
ü is written as u when there is no ambiguity (such as ju, qu, and xu), but written as ü when there are corresponding u syllables (such as lü and nü). In such situations where there are corresponding u syllables, it is often replaced with v on a computer, making it easier to type on a standard keyboard.
When preceded by a consonant, iou, uei, and uen are simplified as iu, ui, and un(which do not represent the actual pronunciation).
As in zhùyīn, what are actually pronounced as buo, puo, muo, and fuo are given a separate representation: bo, po, mo, and fo.
The apostrophe (') is often used before a, o, and e to separate syllables in a word where ambiguity could arise, especially when omitting tone marks, e.g., pi'ao (simplified Chinese: 皮袄; traditional Chinese: 皮襖) vs. piao (票), and Xi'an (西安) vs. xian (先).
Eh alone is written as ê; elsewhere as e. Schwa is always written as e.
zh, ch, and sh can be abbreviated as ẑ, ĉ, and ŝ (z, c, s with a circumflex). However, the shorthands are rarely used due to difficulty of entering them on computers.
ng has the uncommon shorthand of ŋ.
Most of the above are used to avoid ambiguity when writing words of more than one syllable in pīnyīn. For example uenian is written as wenyan because it is not clear which syllables make up uenian; uen-ian, uen-i-an and u-en-i-an are all possible combinations whereas wenyan is unambiguous because we, nya, etc. do not
exist in pīnyīn.

from Wikipedia
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