Introduced in 1958 after years of development at the demand of the Chinese government, the "pinyin" system exists to approximate words in Mandarin Chinese to their equivalent spellings in the Roman alphabet. As a result, the pronunciation of Chinese words has been standardized, although there are several rules to keep in mind -- even those pinyin transcriptions which appear similar to words in English or other Western languages are pronounced very differently. Additionally, each pinyin transcription indicates a "tone," which specifies the intonation with which you must pronounce a word.
Determine the tone of a given pinyin word. Mandarin Chinese has four tones -- "flat," "rising," "falling-rising" and "falling"-- and a fifth "neutral" tone. Pronounce a word with a flat line above its vowel in a high, steady tone; one with an upward-slanting line with a low tone that quickly gets higher; one with a "v" shape with a falling tone that immediately comes back up to where it began; one with a downward-sloping line with an abrupt, almost angry tone.
Pronounce the letter "c" as a mono-syllabic combination of the letters "t" and "s." The word "cai," for example, when spoken in fourth tone, means "dish." Pronounce this word as "tsai." Practice repeatedly until you can say all the sounds in a single syllable.
Replace the "i" sound at the ends of words with "u" (as in the word "push"), unless these words begin with "q" or "i," in which case you pronounce the "i" as "e" in "be." For example, the word "shi" means "to be" when pronounced in fourth tone, but is pronounced as "shu," keeping in mind the "u" sound from the word "push."
Pronounce the letters "q" and "x" as "ch" and "sh," respectively, keeping in mind that the letter "x" occasionally veers more toward "s" in its pronunciation in certain areas of China. Pronounce the word "qing," which means "please" when said in first tone, as "ching." The Western Chinese city of "Xi'an," on the other hand, is pronounced "She-an."
Emphasize the separation between syllables of words which contain apostrophes. The word "ping'an" means peace, but you must define the space between the syllables. Practice saying the word by speaking the first syllable, allowing your mouth to relax for an instant, then saying the second one.