For all of them the lungs push air through a narrow opening where it causes friction of various kinds. /f, W, s, F, h/ are voiceless consonants while /v, T, z, V, r/ are voiced consonants.

• 然后气流从上齿和下唇之间冲出，但上齿和下齿仍保持不动。不振动声带，发/f/音；振动声带，则发/v/。