TONE CHANGES 1. The 3rd tone is a changeable tone. When two 3rd tones come together, the first 3rd tone should be changed into a 2nd tone, e.g., nĭhăo (你好hello) should be pronounced níhăo.
2. When a 3rd tone is followed by a 1st, 2nd, 4th or neutral tone, the 3rd tone should be pronounced as a low 3rd tone. In other words it is a low sustained tone, e.g., as in jĭnzhāng (紧张nervous) and jiĕfàng (解放liberate). Both jĭn and jiĕ stay in the lower part of your voice and you don’t move the sound up.
3. Only under the following situations should the 3rd tone be pronounced as a proper 3rd tone:
when a 3rd tone is on its own. For example, the mono-syllabic expression hăo (好 OK, all right).
when a 3rd tone is at the end of a sentence or a phrase, e.g. fànghăo (放好 to put [something] properly.)
4. When a sentence has three third tones next to each other, it can be changed into the following two patterns:
lower third, second and proper third.
For example: wŏ hĕnhăo (我很好I am fine) should be pronounced wó hénhăo.
THE NEUTRAL TONE The neutral tone is a short and light tone, as described above. The best way to remember how to pronounce the neutral tone is to remember its length and its pitch as follows:
The syllable before the neutral tone should be pronounced longer, as if it is a crochet in music notation and the neutral tone as a quaver.
A neutral tone should be in the middle range of your voice. If a neutral tone is preceded by a low tone such as a third (curved) tone or a low ending tone such as a fourth (falling) tone, the neutral tone should end up at a higher pitch than the preceding tones; if a neutral tone is preceded by a first (sustained) tone or second (rising) tone, the neutral tone should end at a lower pitch than the preceding tones.
RULES FOR PLACING THE TONE MARK Briefly, the tone mark should always be placed over the vowel letters and by the order--a, o, e, i, u, ü, with the only exception being iu, where the tone mark is placed on the u instead.
An algorithm to find the correct vowel letter (when there is more than one) is as follows:
If there is an a or an e, it will take the tone mark.
If there is an ou, then the o takes the tone mark.
Otherwise, the second vowel takes the tone mark.
Worded differently,
If there is an a, e, or o, it will take the tone mark; in the case of ao, the mark goes on the a.
Otherwise, the vowels are -iu or -ui, in which case the second vowel takes the tone mark.
If the tone is written over an i, the tittle above the i is omitted, as in yī.