# 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 - 通常是 t 处于重音音节开头的时候才会被正常读出，比如，*take* teɪk；
> * Standard t - This is the typical pronunciation, 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/l 之前的 t 有可能变成喉塞音 ʔ，比如，*utmost* ˈʌʔˌmoʊst, *fitness* ˈfɪʔnəs, *witness* ˈwɪʔnəs, 或 *fruitless* ˈfruːtləs。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 m/n/l might transform into a glottal stop, as in *utmost* ˈʌʔˌmoʊst, *fitness* ˈfɪʔnəs, *witness* ˈwɪʔnəs, or *fruitless* ˈfruːtləs. 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, ˈwɪntəris also correct.