Answer: Many psychologists have classified declarative knowledge. Ausubel divides meaningful phonetic learning into representation learning, concept learning and proposition learning. These categories are typical declarative knowledge learning.

(1) representation learning. Representation learning, also known as symbol representation learning, refers to learning the meaning of a single symbol or a group of symbols, that is, learning what they represent. The main content of symbolic representation learning is vocabulary learning, that is, learning what words represent.

(2) Concept learning. Concept learning is divided into two situations: one is concept learning, that is, the process of summarizing the common essential characteristics of similar things with some symbols. Concept is to master the key essential characteristics that distinguish it from similar things. The second is conceptual assimilation, that is, the essential characteristics of similar things are directly presented to learners in some way.

(3) Proposition learning. Proposition learning is essentially learning the relationship between several concepts. Propositions can be divided into two categories: one is an unusual proposition, which only expresses the relationship between two or more special things. Proposition learning is generally more complicated than concept learning, and proposition learning must be based on concept learning. The other is a general proposition, which indicates the relationship between several things or properties.