The initial, rhyme and tone in a syllable must belong to the same time level.
同一个词的音节内部的声母、韵母和声调应属同一层次。
2
The consonant that begins a syllable is called an initial and there are 21 of them in modern Chinese (the international Phonetic Alphabet in the brackets).
一个音节开头的辅音叫做声母。现代汉语一共有21个声母(方括弧内是国际音标)。
3
Such syllables are called "zero initial consonant" of a syllable.