# 2.1.8. `ɑː/ɔː`
这一对元音在发声的时候，嘴唇动作非常明显，要在嘴唇形成一个小的圆形之后才开始发音。
When pronouncing this pair of vowels, the lip movement is very noticeable. It's important to form a small circle with lips before beginning to vocalize.
在 CEPD 里，美音 `ɑː` 实际上对应的是英音里的短元音 `ɒ`。在美音里，`ɑː` 可以被理解为是个半长元音。
In the Cambridge English Pronouncing Dictionary (CEPD), the American English vowel sound `ɑː` actually corresponds with the short vowel sound `ɒ` in British English. In American English, `ɑː` can be understood as a half ong vowel.
与英音的 `ɒ` 相比，美音的 `ɑː` 会嘴巴张得更大一点，读得更长一点，听起来更像 `ɑ`，但口型略圆。比如，*dog*, 英音是 `/dɒg/`, 美音却是 `/dɑːg/`；而 *God*, 英音是 `/gɒd/`，美音同样相对更长一点，`/gɑːd/`。
Compared to the British `ɒ`, the American `ɑː` is pronounced with a slightly more open mouth, held a bit longer, and sounds more like `ɑ`. However, the shape of the mouth is slightly rounded. For instance, for the word *dog*, in British English, it's pronounced as `/dɒg/`, while in American English, it's pronounced as `/dɑːg/`. Similarly, for *God*, it's `/gɒd/` in British English, but in American English it's elongated to `/gɑːd/`.
另外，在重读音节里，`ɔː` 可能会被美国人儿化，读成 `ɔːr` ，更像是双元音 `ɔər`。比如，*more* `/mɔːr/`。
Additionally, in *stressed* syllables, `ɔː` might be rhotacized by Americans to sound like `ɔːr`, resembling the diphthong `ɔər`, for example, *more* `/mɔːr/`.