Yan: Autumn goes and spring comes, so there is no definite destination, so sometimes it is compared to impetuous or heartless, such as "from the beam, gulls in the water meet each other" and "Swallow beam is too heartless". But the situation is more complicated, because swallows are relatively common birds and are often used in writing spring scenery in poetry. Many times, I just write about the scenery, and I don't have to include some feelings.

Yan: As opposed to Yan, it is often used to describe autumn scenery. Emotional color is often more sad, reflecting more homesickness. Goose is also a symbol of ancient communication, with the code name of "Hongyan delivers books", so it can also express the thoughts of relatives or close friends. For example, "who sent the brocade book, the word geese returned, and the moon was full of the West Building."