Grammar Point
A Keyphrase should be a short phrase that brings to mind and helps to remember the information on this frame.
(not) well, (not) properly, (not) enough, (not) sufficiently, (not) satisfactorily, (not) decently
with negative verb
The structure
The adverb
I didn't sleep well.
彼は
He doesn't eat properly.
I couldn't speak properly.
I don't have enough money.
Note
This expression is always used with a negative verb. Using it with a positive verb is ungrammatical. It emphasizes the lack of a proper or sufficient action.