In Mandarin, when two third tones are read together, the first third tone is pronounced as a second tone, but the tone mark remains a third tone. This tone change is called Tone Sandhi. For instance,
The original tone of "yi" is the first tone, but when"yi" is before the first, second or third tones, it is pronounced in the fourth tone. For example,
When "yi" is followed by the fourth tone, it is pronounced in the second tone. For instance,
The original tone of the character "bu" is the fourth tone, and "bu" is pronounced in the original tone before the first, second and third tones. For example,
Similar to "yi" when "bu" is followed by the fourth tone, it is pronounced in the second tone. For instance,
