2. Hierarchical deviation method: that is, according to the last pronunciation of couplets, the upper and lower couplets are distinguished. If the last word of the couplet is pronounced in the third or fourth tone in Putonghua (we call it a flat tone), then this is the couplet in the couplet. If the last word is pronounced in the first or second sound (we call it horizontal deviation), then this is the second couplet in the couplet.
3. Meaning division: Some couplets will give up flat tones in pursuit of meaning. If the seller doesn't tell you clearly which is the couplet, you can distinguish them by the meaning of the couplet. Generally speaking, there is a certain causal logic relationship between the upper and lower couplets. At this point, the cause can be regarded as the upper part and the fruit can be regarded as the lower part.