Some consonants form yin-yang pairs: p and b, t and d, f and v, l and r, k and g, s and z. The members of a pair are similarly articulated. The articulation of one member has a yin quality; that of the other, a yang quality. A consonant pair initiates pairs of words differing only in the first letter. The meaning, or part of speech, of one of the words in a word pair has a yin quality; that of the other, a yang quality. Yin qualities are empty, dark, cold, weak, soft, passive, quiet; and yang qualities are full, light, hot, strong, hard, active, loud. Nouns denote things in passive states, which is yin. Verbs denote action, which is yang.
P and B
P and b are bilabial, stop consonants. Bilabial consonants are articulated with both lips. During the articulation of stop consonants, the voice tract is momentarily obstructed completely before being opened to produce a sound. P is voiceless, which means the vocal chords are apart from each other and not moving during its articulation. This makes p yin. B is voiced, which means the vocal chords are together and vibrating during its articulation. This makes b yang.
Pore and Bore
Pore is yin, because it is a noun, and because it means emptiness. Bore is yang, because it is a verb, and because it means to pierce with a turning movement of a tool. A tool fills space, a yang quality.
A pore is the result of boring, just as yin results when yang reaches its limit.
T and D
T and d are alveolar, stop consonants. Alveolar consonants are articulated with the tongue against the upper alveolar ridge. The upper and lower alveolar ridges contain the teeth sockets (alveoli). T is voiceless, which makes it yin. D is voiced, which makes it yang.
Task and Do
A task is a piece of work which has to be done. Again the yin-yang interplay within the word pair can be seen in the fact that the completed task is the result of doing.
F and V
F and v are labiodental, fricative consonants. Labiodental consonants are articulated with the lower lip and upper teeth. Fricative consonants are articulated by partial obstruction of the voice tract, resulting in increased friction between the air stream and the articulators, and a hissing sound. F is voiceless, which makes it yin. V is voiced, which makes it yang.
Fertile and Virile
Fertile is an adjective applied to farmland or the female of a species that receives and nourishes seed, then brings forth the plant or animal corresponding to the seed. Fertility contains the yin meaning of ability to receive. Virile is an adjective applied to the male of a species that produces seed, then passes it on to the female of the species. Virility contains the yang meaning of ability to give.
L and R
Lex and Rex
A law, lex, is made by a king, rex. Rex is a noun, but it denotes a person who performs a certain activity (yang), the result of which is the passive idea of lex (yin). The rex writes the letter of the law.
Left and Right
Most people are right-handed, which means that their right hands are stronger (yang) than their left hands (yin).