# 3.2.12. `ts/dz`

`ts/dz` 和 `s/z` 不一样的地方在于发声时起始的舌尖位置，`s/z` 起始的舌尖位置贴近但没有接触到牙齿和牙龈的接缝处；但，`ts/dz` 的舌尖要再往后一点，和 `t/d` 发声时起始的舌尖位置一样，贴在龈脊的那个部位之后开始发声。

The difference between `ts/dz` and `s/z` lies in the initial tongue position during pronunciation. For `s/z`, the tip of the tongue is close to, but not touching, the *seam* of the teeth and gums. However, for `ts/dz`, the tongue tip is a bit further back, identical to the initial position when pronouncing `t/d`. It starts pronouncing from that spot of the *alveolar ridge*.

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可以用 *students* `/ˈstudənts/` 这个词反复体会 `s`、`d`、`ts` 的舌尖位置（注意，开头的 `st` 会被读成 `sd`）……

The word *students* `/ˈstudənts/` can be repeatedly pronounced to understand the tongue positions for `s`, `d`, and `ts` (note that the initial `st` is pronounced like `sd`).