Video Text:

[t] and [d] are paired together because they take the same mouth and tongue position. T, tt, is the unvoiced, meaning only air passes, and D, dd, is voiced with means you actually make sound with the vocal cords. The position: the teeth are together, and the tip of the tongue touches the roof of the mouth. It's about halfway between the very front, where the teeth are, and midway. So, it's about a quarter of the way back. And, it's just the tip of the tongue that touches. The sound is made when the tongue pulls away from the roof of the mouth and forces extra air through the teeth.我把[t]和[d]放在一起讲，是因为它们发音时的嘴部和舌头的位置是一样的。T，tt，是不发出声音的清辅音，也就是只有气流通过，而D，dd，是发声的浊辅音的，也就是说声带要振动发声。口腔发音位置：牙齿紧贴在一起，舌尖抵住上颚。大概在上颚的中间与牙齿距离的一半位置，也就是在靠近齿龈的四分之一处。而且接触的位置仅仅是在舌尖。当舌头从上颚弹开，使气流冲出即为此发音。

Word pairs:

tad 少量—dad 爸爸

till 直到—dill 莳萝

tote 手提袋—dote 溺爱

tan 黄褐色的—Dan 丹（人名）

Ted 泰德（人名）—Dead 死去的