Pinyin is the process of reading syllables, i.e. to piece together quickly the shengmu and yunmu and make it a syllable by adding the tones according to the structural rules of the syllables in Putonghua. The main points for Pinyin is: "The shengmu should be pronounced lightly and shortly while the yunmu should be pronounced strongly. The shengmu and yunmu shall be joined together suddenly and quickly."

When reading a Pinyin, you should remember the following rules of joining shengmu and yunmu in Putonghua:

• Both the shengmu n and the lingshengmu can be joined together with Kaikouhu, Qichihu and Cuokouhu.
• The shengmu f, g, k, h, zh, ch, r, z, c and s can only be joined together with Kaikouhu and Hekouhu.
• The shengmu j, q and x can only be joined together with Qichihu and Cuokouhu.
• The shengmu b, p, m, d and t cannot be joined together with Cuokouhu.
• The yunmu of Kaikouhu and Hekouhu can be joined together with all shengmu except for j, q and x.
• The yunmu of Cuokouhu can only be joined together with j, q, x, n, l and lingshengmu.

You must also pay attention to the exact pronunciation of the value of shengmu, yunmu and tones. When reading a Pinyin, you must read the "original pronunciation" of the shengmu instead of Huduyin (Huduyin means the pronunciation of shengmu with different vowels added at the end). You should also take the yunmu as a whole. Do not separate the yuntou, yunfu and yunwei before piecing them together. Be sure to see clear the tone marks and pronounce exactly the tone pitch.

There are several common reading methods as follows:

• Take the yunmu as a whole and join it together with the shengmu. For example: h-ào→hào.
• Make your vocal organ in the exact position of pronouncing the shengmu, then pronounce the yunmu. For example, when reading bā, you should close your lips first and make the vocal organ in the position of pronouncing b; then pronounce a and make them a syllable.
• Separate the syllable with an intermediate vowel into three parts, i.e. shengmu, intermediate vowel and yunmu, then read the three parts continuously and make them a syllable. For example, q-i-ánɡ→qiánɡ.
• Piece together the shengmu and the intermediate vowel and make them one part of the Pinyin, then join this part together with the following yunmu. For example: ɡu-ānɡ→ɡuānɡ.

Syllables in Putonghua are not isolated from others. When reading syllables continuously, the tones of the syllables will influence on each other and thus change their original tone pitch more or less. This is called tonal modification. Tonal modification is a natural phenomenon and does not have any effect on expression.

The third tones before the first, second, third or fourth tones will all be tonally modified. In fact, the third tone is seldom pronounced as its original tone except when it is pronounced individually or when it is at the end of a word or a sentence. There are two kinds of situations for the tonal modification of the third tone:

• The third tone before the first tone, the second tone, the fourth tone or light tone shall be modified to half-third tone, i.e. only the first half of the third tone is read out without the second half. For example, shǒuxiān (首先), zǔguó (祖国), guǎngdà (广大) and ěrduo(耳朵).
• The third tone before the third tone shall be modified to the same tone pitch as the second tone. Such as shǒubiǎo (手表), gǔdiǎn (古典), měihǎo (美好) and lǐxiǎng (理想).

yī:

• When yī is read individually or is at the end of a word or a sentence, it should be pronounced in the original tone, the first tone.
• When it is before the fourth tone, it should be modified to the second tone.
  Examples:
  

  一道yídào	一次yícì	一定yídìng	一致yízhì	一律yílǜ
  一晃yíhuàng	一动yídòng	一并yíbìng	一刻yíkè	一路yílù

• When it is before the first, the second and the third tone, it shall be modified to the fourth tone.
  Examples:
  before the first tone:
  一般yìbān 一端yìduān 一经yìjīng 一边yìbiān
  before the second tone:
  一时yìshí 一群yìqún 一条yìtiáo 一团yìtuán
  before the third tone:
  一举yìjǚ 一早yìzǎo 一手yìshǒu 一体yìtǐ
  
• When it is between two same verbs, it shall be modified to the light tone.
  Examples:
  看一看kànyikàn 想一想xiǎngyixiǎng
  问一问wènyiwèn 学一学xuéyixué
  

bù:

• When bù is read individually or is at the end of a sentence, it should be pronounced in the original tone, i.e. the fourth tone.
• When it is before the fourth tone, it should be modified to the second tone.
  Examples:
  不会búhuì 不但búdàn 不论búlùn 不必búbì 不变búbiàn
  不是búshì 不信búxìn 不料búliào 不愧búkuì 不错búcuò
  
• When it is between two adjectives, between two verbs or between a verb and a complement, it should be modified to the light tone.
  Examples:
  好不好hǎobuhǎo 行不行xíngbuxíng
  看不清kànbuqīng 打不开dǎbukāi
  

he light tone is a special kind of tone besides the four tones. In a word or a sentence, some syllables often have their original tones changed into short and light tones. Such short and light tone is called the light tone. All the light tones in Putonghua come from the four tones. The light tone can only be found in words and sentences and does not exist by itself.

For some words, you can differentiate their meanings by using the light tone. For example, xiōng di means the younger brother while xiōng dì means brothers.

For some other words, you can differentiate their meanings and the nature of words by using the light tone. For example, duì tou is a noun and means enemy or opponent, while duì tóu is an adjective and means proper or right.

In addition, some double-syllable words have their second syllable pronounced in the light tone. It is just a habit and such light tone cannot differentiate meanings or nature of words. For example, shénqi (神气), shāngliang (商量) and zhàngfu (丈夫).

There are some rules for determining if a word should be pronounced in the light tone:

• The auxiliary word of mood, such as ba (吧), ma (吗), ne (呢) and a (啊), should be pronounced in the light tone. For example, xíng'a (行啊), hǎoba (好吧), qùma (去吗).
• The auxiliary word, such as 的, 地, 得, 了, 过and们, should be pronounced in the light tone. For example, dàde (大的), xiěle (写了), mǎideqǐ (买得起).
• The suffixes to nouns, such as zǐ (子), ér (儿), tóu (头), should be pronounced in the light tone. For example, zhuōzi (桌子), guàntou (罐头), nǚ'er (女儿).
• The nouns of direction or locality should be pronounced in the light tone. For example, tiānshang (天上) and jiāli (家里).
• The last syllable of reduplication verbs should be pronounced in the light tone. For example, kànkan (看看).
• The last syllable of reduplication nouns should be pronounced in the light tone. For example, gēge (哥哥), wáwa (娃娃), xīngxing (猩猩).
• The directional verbs should be pronounced in the light tone. For example, guòlai (过来), guòqu (过去), gànqilai (干起来).

The change of the light tone is unstable. When learning pronunciation, you should master those fixed light tone words, i.e. the words already included in the dictionaries. As for the syllables that can be pronounced both in the light tone and the original tones, we usually do not pronounce it in the light tone.