The former is known as the Manner of Articulation and the latter as the Place of Articulation (or the Place of Articulatory Gestures).

发辅音时至少需两个发音器参与，例如 bad 一词起首音 [b] 涉及双唇闭合音姿，末尾音 [d] 涉及舌叶 (或舌尖) 向齿龈运动音姿。因此，辅音分类考虑到若干因素，其中最是：①发音器之实际关系，经过声道某些部位时方式；②声道哪些部位出现靠拢、变窄或发生阻碍。前者称为 “发音方式”，后者叫作 “发音部位”。

They're all produced with the tongue near to or actually touching that ridge behind the upper teeth, which is technically called the alveolar ridge.

它们都是通过将舌头靠近或实际上触及上牙后方齿龈脊发出，这一部位在语音学上被称为齿龈脊。

In some other languages, the front part of your tongue does have contact with the bump or some part of the roof of your mouth.

在一些其他语言中，你舌头前部确实会与齿龈或口腔顶部某部分接触。

In some forms of American English, the flap occurs for ''t'' in words like dirty and sorting, after r -colored vowels in a stressed syllable.

(7) 触音和闪音：当舌对齿龈进行一次触及，发生一次颤动，就是触音。在美国英语中，像 [t， d] 等音常常发成触音，如 city (城市) 和 ladder (梯子) 等。闪音是首先以卷舌音音姿将舌尖向上并向后卷曲，然后返回下齿后面位置，在齿龈后区域击打口腔顶部。在美国英语一些方言中，闪音出现在读音节中儿化元音之后，如 dirty (脏) 和 sorting (分类)(Ladefoged&Johnson， 2015： 99；关于儿化元音见下文 2.2。