Spanish pronunciations of t and d and b and p

About t and d:

t is a voiceless sound. The "top" of the tongue on the roof of the mouth sounds very crisp and does not change with the position of the letter in the word, such as tasa and detener. There is no difference between t and t~~

d is a voiced sound. The tongue is "attached" to the roof of the mouth, and the pronunciation is thicker. Different positions in the word will also affect the pronunciation. For example, in dar, d is very strong. /d/ sound; but when it comes to words such as hada, the sound of d is equivalent to /?/ in English, that is, the tip of the tongue is slightly away from the roof of the mouth, allowing the airflow to leak~; if it is at the end of the word, such as usted, the d is weakened to the point where it is almost audible Less than, but pronounced /?/

b and p:

p is unvoiced and easy to pronounce, similar to b in Chinese Pinyin;

b (pronounced the same as v) is a voiced sound. When it is at the beginning of a word or after m or n (base, beso, un vaso), you should pay attention to the "closed" lips when pronouncing it, and the airflow will rush out, which can be obvious. Feel the vibration of the vocal cords; in addition, when in the word (lobo, pavo), there is also /?/, which is a fricative sound. The lips are "not closed" when pronouncing, leaving a gap for airflow to pass. The Chinese word "tile" and the English word /v/ are both wrong~