Tone 4 Pronounced as Tone 2

• The native speaker's tone contour of Mandarin Tone 4 in “綴” shows dramatic falling trend, from 380Hz at the beginning to 120Hz at the end of the utterance.
• The learners' tone contours of “綴” show rising trend in the middle of their utterances, differences between minimum and maximum pitch values are around 50-70Hz.

• The native speaker's reading of “踏” in the word “践踏” exhibits a dramatic falling trend, from 310Hz at the beginning to 150Hz at the end of the tone contour.
• The learners' reading of “踏” in the word “践踏” show slow rising trend from the middle of the tone contour, differences between minimum and maximum pitch values are 30-80Hz.

Suggestions for teachers:

• remind students to have high pitch onset at the beginning of Tone 4 pronunciation, and keep falling throughout the pronunciation.
• remind students to keep high pitch at the beginning of Tone 4 pronunciation when the offset of the preceding word is low.