Pinyin (拼音 Pin1 Yin1) literally means "spelling according to sounds" in Mandarin. It is a system of romanization (phonetic notation and transliteration) for the Mandarin dialect used in the People's Republic of China (approved in 1958 and adopted in 1979 by its govenment). It superseded older transcriptions like the Wade-Giles system (1859; modified 1912) or Bopomofo or Zhuyin. Since then, Pinyin has been accepted by most international institutions as the transcription system for Mandarin. The Republic of China (Taiwan), however, didn't take it over due to political reasons and continued to use the Yale transcription.
Pinyin uses the Roman alphabet, hence the pronunciation is relatively straightforward for Westerners. A pitfall for novices is, however, the unusual pronunciation of "x", "q" and (for English speakers) "c" and "z". The sounds represented by "x" and "q" in Western languages don't exist in Chinese, so the Pinyin system "recycles" them and assigns them other sounds: "x" represents a soft "sh" (like the "sh" in "sharp" but not as fully sounding), "q" represents a soft "ch" (again, like the "ch" in "chin" but not quite). The "c" is pronounced like "ts", "z" like "ds". Finally, "ü" stands for the same sound as in German and "u" is pronounced like "ü" if it follows "y", "x", "j" or "q".
If you obey these basic rules, you will still sound somewhat strange to a Chinese, but you'll be on the right track.
More detailed pronuciation rules:
- a: as in "father"
- ai: like English "eye", but a bit lighter
- an: as in "can" if following "y", as in "unbelievable" otherwise
- anr: like a, but pronounced with the tongue curled up against the palate
- ao: approximately as in "cow"; the a is much more audible than the o
- b: unaspirated "p", like the English "b" but with a bit more pressure
- c: like "ts"
- ch: as in "chin"
- d: unaspirated "t", like the English "d" but with a bit more pressure
- e: a backward, unrounded vowel, which can be formed by first pronouncing a plain continental "o" and then spreading the lips without changing the position of the tongue; when followed by "n", it is pronounced more like the first sound in "an"
- ê: as in French "ecole"
- ei: as in "hey"
- er: like e, but pronounced with the tongue curled up against the palate
- f: as in English
- g: unaspirated "k", like the English "g" but with a bit more pressure
- h: like the English "h" if followed by "a"; otherwise it is pronounced more roughly (not unlike the Scottish "ch")
- i: like English "ee", except when preceded by "c", "ch", "r", "s", "z" or "zh"; in these cases it sounds similiar to e (described above), but not as open
- ie: the initial i sounds like English "ee", but is very short; e (pronounced like ê) is pronounced longer and carries the main stress
- iu: pronounced like iou
- j: like zh, but not as "full", about halfway between zh and z
- k: as in English
- l: as in English
- m: as in English
- n: as in English
- o: an open continental "o", as in German "Hof"
- ong: here, o is a sound somewhere in between English "o" as in "song" and English "u" as in "bush"
- p: as in English
- q: like ch, but not as "full", about halfway between ch and c
- r: similiar to the English "r" in "rank" with a bit of the initial sound in French "journal" in it (I know this sounds strange at first, but try it!)
- s: as in "sun"
- sh: as in "shinbone"
- t: as in English
- u: like English "oo", except when preceded by y, x, j or q; in this case it is pronounced like ü
- uo: the u is pronounced shorter and lighter than the o
- ü: as in German "üben" or French "lune"
- üe: e is pronounced like ê, the ü is short and light
- w: as in English; not pronounced at all if followed by u
- x: like sh, but not as "full", about halfway between sh and s
- y: as in English; not pronounced at all if followed by i or ü
- z: like ds, but with more pressure (unaspirated counterpart of c)
- zh: as in English "jungle", but with more pressure (unaspirated counterpart of ch)
Sometimes the boundaries between syllables aren't obvious. In this case, they are separated by an apostrophe. For example, the word "xian" could either be pronounced as one syllable or as two ("xi-an"). In the latter case, it would be written as "xi'an".
The "full" Pinyin system additionally uses tone marks (written above the vowels) to represent the four tones of Mandarin. The first tone (high level tone) is represented by a macron ("bar"), the second one (rising tone) by an acute, the third one (low tone) by a reversed circumflex ("wing") and the fourth one (falling tone) by a grave accent. Vowels without tone are left unmarked. These tone marks normally are only used in Mandarin textbooks, but they are essential for correct pronunciation of Mandarin syllables.
Since most computer fonts don't contain the macron or reverse circumflex accents, another commonly used convention is to postfix the individual syllables with a digit representing their tone (e.g., "tóng" is written "tong2")
This needs thorough checking. I'm not a linguist and not an English native speaker, so my descriptions of how to produce the individual sounds may be wrong or misleading...