The most important tone sandhi is that of tone-3. Each of the two forms of bisyllabic sequences in Chinese, the quasi-iambic and the trochaic, has two types of tone sandhi pattern. As far as the quasi-iambic sequence is concerned, tone-3 followed by other tones (including the neutral tone) except another tone-3 changes to ½ tone-3. Tone-3 followed by another tone-3 changes to tone-2. As far as the trochaic sequence is concerned, tone-3 followed by the neutral tone derived originally from tone-3 changes either to ½ tone-3 as before any other neutral tone, or to tone-2 as before any stressed tone-3. Tone-3 followed by the first type of trochaic sequence changes to tone-2, and that followed by the second type changes to ½ tone-3. Tone sandhi patterns of the sequences formed by three stressed tone-3 syllables, though mostly determined by the IC, are rather inconsistent; they vary from speaker to speaker. There are two types of tone sandhi patterns of the sequences formed by more than three stressed tone-3 syllables. The first type is uttered with a momentary pause which has the function of separating one IC from another. The second type is uttered without the pause. Thus only the tone pattern of the final syllable remains unchanged. Whether a polysyllabic sequence is uttered with a momentary pause or not depends on the speaker. In general, due to the influence of stress distribution, 223-sequences and 2223-sequences may optionally change to 213-sequences and 2123-sequences respectively when they are spoken faster. This confirms that the description of sandhi patterns in the second paragraph of section 1 is correct.