The structure 没…没… is used to form set expressions in colloquial speech. It is used in the following two cases.
The first case is to express someone's inability to distinguish between what is right and what is wrong.
"A" and "B" are replaced by adjectives with opposite meanings.
Let's look at some examples.
没大没小 is used in relation to someone who behaves inappropriately.
This is due to the importance of hierarchy in Chinese culture. That is, young people should show respect for their elders.
This child speaks out of turn
zhè háizi shuōhuà méi dà méi xiǎo de
There is another example used to express rudeness and bad manners:
This girl has no sense of decency at all. She interrupted our conversation
zhè yātou, dǎduàn wǒmen de tánhuà, méi qīng méi zhòng de
The second case is to intensify the meaning.
"A" and "B" can be replaced by nouns, adjectives or verbs with a similar meaning.
I'm starving. I haven’t eaten or drunk anything all morning