To understand a poem, we should start with the following points.
Categories and characteristics.
There are long and short ancient poems, and there are same words and miscellaneous words, that is, the words used in each sentence are the same, or the words used in each sentence are different. In Qi Yan, there are five or seven words. You must first make a judgment in your mind about the poem you are reading.
The ancients read and wrote poems, paying the most attention to poetic style.
Because different styles of poetry have different ways of writing, in ancient poetry, ancient style is ancient style, songs are songs, and Yuefu is Yuefu. In modern poetry, five-character, seven-character poems and quatrains are written in different ways.
2. The law of poetry pursuit.
There are strict rules in the meter, the rhyme must be balanced, and the harmony between sentences should be paid attention to. Seven words stipulate the level of each word in a sentence. In the past, the so-called "135 is indistinguishable, 246 is distinct", but to avoid isolation and three-level tone, the two couplets in the middle of metrical poems should be opposed. These are the basic requirements.
For example, Qian Qi's "Try to Fragrant and Gulingse" is five words and six rhymes, but it is actually a five-word arrangement. There is also a seven-character arrangement, which is more in later generations. It seems that every sentence is seven words with a seven-character song line, but it is different with a flat tone and cannot be confused.
There is another situation that needs attention. The quatrains are not all metrical poems, but there is an archaic quatrains, which is called "archaic quatrains" for short. It's the same four sentences, but it doesn't follow the rules. Ancient classics existed in the Han Dynasty, and many famous works in Tang poetry are actually ancient classics. For example, Meng Haoran's "Spring Dawn" and Liu Zongyuan's "Jiang Xue" all rhyme and belong to ancient rhyme, while Jiang Xue still enters the rhyme, and the rhymes such as "Jue", "Jue" and "Snow" all enter the tone.
How to distinguish ancient poetry from modern poetry?
According to the formal standards of these ancient poems and modern poems, we can judge whether a poem is ancient or modern. For example, Wang Bo's famous poem Teng Wang Ge:
Wang Teng Linjiang Zhu and Ming Luan went dancing.
The painted building faces Nanpu Cloud, and the bead curtain rolls up the rain in the western hills at dusk.
The shadow of the idle cloud pool is long, and things change for a few years.
Where is the emperor in the cabinet today? Outside the threshold, the Yangtze River flows by itself.
We can see that the seven rhymes are equal in sound and rhyme. The rhyme of this poem is dance, rain, autumn and flow. The first two are stop sounds and the last two are flat sounds, which of course does not meet the requirements of seven rhymes. Moreover, according to the principle of adhering to the right, the words "Jiang" and "Song" in the first two sentences can only be flat and even, and not both. Now "Jiang" and "Song" are all flat tones, which of course does not conform to the provisions of the Seven Laws. Looking at the antithesis, the Seven Laws require that the two couplets in the middle should be antithetical. The couplet "The painted building flies to Nanpu Cloud, and the rain is rolling in the western hills at dusk" is a couplet, but the bottom couplet "The shadow of a floating pool is long, and things change for several years" is beautiful, but it is obviously not a couplet. It can be seen that Wang Bo's Poem of Tengwangge is not a seven-character poem, but an ancient poem with seven characters.