Adjectives can be divided into two kinds, scalar and absolute.
A scalar adjective such as好 ( h˘ao/ to be good) denotes a property that can be calibrated in degrees and can be modified by an adverb like 很 (hˇen/ very). For example, in the sentence這個答案很好 (zh`e-ge d´a’`an hˇen h˘ao/ This answer is very good.), 好 (h˘ao/ to be good) is a property that can be possessed in varying degrees. Therefore, this adjective can be modified by the degree modifier 很 (hˇen/ very).
On the other hand, an absolute adjective indicates a property that cannot be calibrated and normally cannot be modified by the degree adverb. Hence, 這個答案很錯 (zh`e-ge d´a’`an hˇen cu`o/ This answer is very wrong) is an ungrammatical sentence, as the non-gradable adjective 錯 (cu`o/ wrong) cannot be modified by the degree adverb 很 (hˇen/ very).
Reference: Chinese: a linguistic introduction by Chao Fen Sun