We have learned that Chinese is derived from picture writing, known as pictographs which have no relation to the sound of a word. Gradually they gave way to non
pictorial characters, in addition to standing for tangible objects, also represented abstract concepts. Later they formed an important principle for new
coined characters, among of which, also the most important, is called xíng shēng zì. They consist of two parts: a “signific”, which indicates that it has something to do with a meaning, and a "phonetic", which indicates the sound.
Let’s take a look at the following Characters:
mā ma
妈 妈 : 女(women, signific part)+ 马(phonetic part)
jiě jie
姐 姐: 女 (women, signific part)+ 且 (phonetic part)
wá wa
娃 娃 : 女(women, signific part)+ 圭 (phonetic part)
qīng wā
(青)蛙 : 虫 (insects, signific part)+ 圭 (phonetic part)
guī
圭 : 土 (mud)+ 土 (mud)
The character圭 refers to a jade held in the hands by ancient rulers on ceremonial occasions. Forget about its meaning. It is seldom used today.
妈、姐、娃、蛙、are called xíng shēng zì, the left half part is signific part. For example, the “女” of 妈、姐、娃 means it has something to do with women. The right half part is phonetic part. As a result of phonetic evolution, many phonetic parts have changed their pronunciations which made them a little different to the character that they combined. You will find圭(guī)pronounces totally different with 娃(wā)and 蛙(wá). But娃 and蛙 have similar pronunciations.