1, explaining the literal meaning of the poem;
2. Make clear what the poet wants to express; (For example, Du Fu's "Wen Guanjun Recovers Henan and Hebei")
3. Introduce the background of the poet's poems; (such as "Chaofa Baidicheng" by Li Bai)
4. Explain the linguistic beauty of poems and sentences (such as green in Jiang Nanan's sentences).