Classical poetry belongs to sentimental poetry, right?

That's right. Qian Zhongshu mentioned Schiller's views on "simple poetry" and "sentimental poetry" here. Schiller thinks that ancient poetry imitates nature, and poetry has natural nature and is sentimental, so it is right. Classical poetry is a genre of poetry. Judging from the number of words in a poem, there are so-called four-character poems, five-character poems and seven-character poems. Four words are four words, five words are five words and seven words are seven words.