The quatrains require more leveling. When learning, you can first understand "rhyme" and learn to distinguish between "flat" and "flat" pronunciation, and then slowly compare the four flat formats of "rhyme" and use them one by one.
The modern seven-character quatrains rhyme the same as the ancient ones. Generally speaking, the last word of each of the first two or four sentences uses the same or similar vowels, which makes you feel sonorous and harmonious when reading or singing. The third sentence doesn't have to rhyme, otherwise it will lose its charm and become a jingle or a doggerel.
Seven-character quatrains are a genre of China's traditional poetry, which belongs to the category of modern poetry. Seven-character quatrains are four poems, each with seven words, which have strict metrical requirements in rhyme and sticky equivalence. The poetic style originated from Yuefu songs in the Southern Dynasties or Yuefu folk songs in the Northern Dynasties or folk songs in the Western Jin Dynasty, and its stereotypes matured in the Tang Dynasty. Representative works include Wang Changling's Poems on Newly Built Lotus Inn, Li Bai's Newly Built Baidicheng, Du Fu's Riverside Meeting Li Guinian, etc.
Rhyme is one of the basic elements of poetry meter. Poets use rhyme in their poems, which is called rhyme. Poetry from The Book of Songs to later generations has almost no rhyme. There are no folk songs that don't rhyme. In the northern operas of China, rhyme is also called "quotation" and rhyme is also called "match".
Seven-character quatrains, the first sentence and the third sentence should end with "Yi", which is completely in line with the requirements of the meter, but the author of this poem uses the word "Yi" in these two positions, which is not in line with the law. If it's a rhyming quatrain, you rarely see the third sentence, and you don't have to consider the rhyme problem, just end with a flat voice.
References:
Baidu encyclopedia-seven-character quatrains