not completely understand
Half understand, Chinese idioms, Pinyin is B à nd à NGB à D à ng, meaning is not all understand, half understand half do not understand. From Kong Yiji.
The origin of Idioms
When he talks to people, he is always full of too much to understand. ——The third lesson plan of junior high school Kong Yiji
Idiom usage
It refers to a person's poor skill.
not completely understand
Gather the bone and blow the soul - liǎn gǔ chuí hún
be ignorant of the present state of affairs - bù shí shí wù