# 3.1.8. `aɪ, eɪ, ɔɪ, eə, ɪə, ʊə, aʊ, əʊ`

亚洲语系基本上都没有和英文一样**长度**的**双元音**。韩文日文的母音和中文的韵母虽然都有少数由两个基础音素构成的组合音，但，它们和英文的双元音不同的地方在于，它们都是和其它韵母或者母音**等长**的，而不是像英文双元音的长度那样几乎是短元音的**两倍**。

Essentially, Asian languages don't have *diphthongs* that are as *long* as those in English. Though Korean, Japanese, and Chinese vowels include a few compound sounds made of two basic vowel phonemes, they differ from English diphthongs. In these languages, the compound sounds are the *same length* as other vowels, not almost *double the length* like English diphthongs.

比如，当中国人说 “太累了” 的时候，“太”（`tài`）这个字的 “韵母” 就很接近英文的双元音 `aɪ`；“累”（`lèi`）这个字的韵母就很接近英文的双元音 `eɪ`…… 但，它们很不一样，英文的双元音就是相对更长。

For instance, when Chinese say *too tired* or "太累了," the syllable `tài` has a vowel sound that closely resembles the English diphthong `aɪ`, and the vowel in `lèi` mimics the English diphthong `eɪ`. Despite these similarities, they're not identical - English diphthongs tend to be *longer* in duration.

英文的双元音，都是两个元音的组合。它们都是从第一个元音**滑**向第二个元音，所以，它们从长度上来看，相当于是长元音；**节奏**在感觉上大抵是乐谱里的 “一拍里均放着三个等长音符的三连音”，前一个音素更长一些，后一个音素相对较短。

In English, diphthongs are a combination of two vowel sounds. They *glide* from the first vowel to the second, making them similar in length to long vowels. In terms of *rhythm*, you can think of them like a triplet in music, where three notes of equal length fit within one beat. The first sound tends to be slightly longer, while the second sound is a bit shorter.

读 `aɪ, eɪ, ɔɪ` 的时候，唇形分别从 `ɑ, e, ɔ` 开始，唇形保持不变，用喉咙完成从其实元音到 `ɪ` 的过度。

When pronouncing the sounds `aɪ, eɪ, ɔɪ`, begin with the mouth shapes for `ɑ, e, ɔ` respectively. Keep lips in the same position and use throat to glide from the initial vowel sound to `ɪ`.

![vowels-mouth-shape-aɪ](/images/vowels-mouth-shape-aɪ.svg)

读 `eə, ɪə, ʊə` 的时候，也一样，唇形分别从 `e, ɪ, ʊ` 开始，唇形保持不变，用喉咙完成从其实元音到 `ə` 的过度。美音会儿化这个 `ə`，所以是 `eər, ɪər, ʊər`，或者干脆写成 `er, ɪr, ʊr`。

When pronouncing `eə, ɪə, ʊə`, it's the same process. Start with the mouth shapes for `e, ɪ, ʊ`, keep lips steady, and use your throat to glide from the initial vowel to `ə`. Americans  tend to *rhotacize* (add an `r` sound to) this `ə`, so it becomes `eər, ɪər, ʊər`. Alternatively, they are written as `er, ɪr, ʊr`.

![vowels-mouth-shape-eə](/images/vowels-mouth-shape-eə.svg)

读 `aʊ, əʊ` 的时候，唇形有变化，要分别从 `ɑ, ə` 开始，而后过度到 `ʊ`。

![vowels-mouth-shape-aʊ](/images/vowels-mouth-shape-aʊ.svg)

When pronouncing the sounds `aʊ, əʊ`, mouth shape should *change*. Start with the sounds `ɑ, ə` respectively, then glide towards the `ʊ` sound.

在读它们的时候，重要的是，要把它们读得**足够长** —— 几乎要占用两个元音的发声时长，并且足够饱满。

When pronouncing them, it's crucial to draw out the sounds - because they're taking the duration of two vowels - and make sure they are full and rich.