Aspiration 送氣 (送气)
sòngqì · from Latin
What is aspiration?
Aspiration is the puff of breath after a consonant such as p, t or k; many Asian languages use it to tell words apart.
In English, aspiration is automatic and never changes meaning. In Mandarin, Pinyin b, d, g are unaspirated and p, t, k are aspirated, so the difference is breath, not voicing. Korean contrasts plain, aspirated and tense stops, and Thai and Hindi use aspiration contrasts too, which is why romanisation often looks confusing.
Examples
爸 bà (dad) vs 怕 pà (afraid); Korean 달 dal (moon) vs 탈 tal (mask) vs 딸 ttal (daughter); Thai ไป pai (go) vs ภัย phai (danger)
Kungfucius says: Hold a tissue in front of your mouth. If it moves for p and not b, you are speaking Mandarin. If it moves for both, you are speaking English.