# 2.2.3 `t/d`
虽然每种语言都有这两个辅音，但，英文的 `t/d` 的发声关键在于起始的舌尖位置 —— 顶在**龈脊**（*alveolar ridge*）上，而不是贴在牙齿上 —— 即，位置 ③（参见 [1.4](1.4-articulators)）。
While every language has the consonants `t` and `d`, the key to pronouncing them in English lies in the starting position of the tip of the tongue - it should touch the *alveolar ridge*, i.e. position ③ (as described in [1.4](1.4-articulators)), not the *teeth*.
在中文普通话里，`t/d` 这两个声母发声时起始的舌尖位置贴在牙齿上；你可以试着用中文普通话说一遍 “我踢死你！”（`wǒ tī sǐ nǐ`）……
In Mandarin Chinese, the starting position of the tongue tip for the `t` and `d` sounds rests on the teeth. You can try this out by saying "wǒ tī sǐ nǐ" (我踢死你！) in Mandarin.
对中国人来说，起初的时候这是个相当难以纠正的习惯，因为舌尖总是不由自主地贴到牙齿上而不是龈脊上 —— 只能通过大量且高密度的练习建立新习惯。
For Chinese speakers, it's a pretty tough to correct at first because the tongue tip instinctively goes to the teeth, not the *alveolar ridge*. It can only be corrected through intense and frequent practice to build a new habit.
另外，就好像 `p/b` 在发音的时候会自然带着一个很轻的 `ʊ` 一样，`t/d` 也会自然带着一个很轻的元音，不过，不是 `ə` 而是 `ɤ` —— 之前提到过，相当于中文里 “思念” 的 “思”（`sī`）的韵母（[2.1.10](2.1.10-ɤ)）。
Additionally, just as the `p` and `b` sound naturally carries a slight `ʊ` sound in its pronunciation, the `t` and `d` sound also carries a light vowel sound. But instead of 'ə', it's `ɤ` - as previously mentioned, this is equivalent to the vowel in the Chinese word for 思, which is `sī.`
在中文拼音里，`i` 在 `t/d` 之后相当于英文音标中的 `i`；在 `z/c/s` 之后的 `i` 才会读成 `ɤ`…… 所以，依据母语的习惯，中国人习惯于将 `t(ɤ)` 读作 `tə`，将 `d(ɤ)` 读作 `də`。需要为此专门建立一个新习惯。
In the Chinese phonetic system, `i` following `t/d` is similar to `i` in English phonetic notation. Meanwhile, `i` after `z/c/s` is pronounced as `ɤ`. So, according to the habits of their native language, Chinese speakers tend to pronounce `t(ɤ)` as `tə`, and `d(ɤ)` as `də`. This calls for establishing a new habit.
`t` 这个音素，也许是美式英语的辅音里最复杂的一个 —— 当然也是最常用的一个。美式英语中，`t` 的变体（allophone）至少有四个：
The `t` sound may be the most complex in American English consonant pronunciations — and certainly one of the most frequently used. In American English, at least four variations, or *allophones*, of `t` exist:
> * 正常音 `t` - 只有 `t` 处于重音音节开头的时候才被正常读出，比如，*take* `/teɪk/`；
> * Standard `t` - This is the typical pronunciation, only used when `t` begins a stressed syllable, as in *take* `/teɪk/`.
> * 弹舌音 `t̬` - 夹在两个元音中间的 `t` 会变成接近 `d` 的弹舌音 `t̬`，比如，*water* `/ˈwɑːt̬ɚ/`；
> * Flaping `t̬`: When `t` is situated between two vowels, it tends to be flaping `t̬`, sounding like `d`, as in water `/ˈwɑːt̬ɚ/`.
> * 喉塞音 `ʔ` - `m/n` 之前的 `t` 有可能变成喉塞音 `ʔ`，比如，*utmost* `/ˈəʔˌmoʊst/`, *fitness* `/ˈfɪʔnəs/`, *witness* `/ˈwɪʔnəs/`。如果你不知道喉塞音是什么样的，听听 *Uh-Oh!* —— `/ʌʔoʊ/`……
> * Glottal Stop `ʔ` - The `t` before `n` might transform into a glottal stop, as in *utmost* `/ˈəʔˌmoʊst/`, *fitness* `/ˈfɪʔnəs/`, or *witness* `/ˈwɪʔnəs/`. If you don't understand what is a *glottal stop*, listen to the phrase, *Uh-Oh!* —— `/ʌʔoʊ/`...
> * 省略音 `ᵗ` - `n` 之后的 `t` 可能会被省略掉，比如，*winter* `/ˈwɪnᵗər/` —— 当然，若是读成 `/ˈwɪntər/`也没错……
> * Optional `ᵗ` - The `t` following `n` might be omitted, as in *winter* `/ˈwɪnᵗər/` - of course, `/ˈwɪntər/`is also correct.