The poem is written in free verse, with a rhythmic and musical quality created by the repetition of certain words and phrases. The language is simple and direct, yet it is also rich in imagery and symbolism. The poem's imagery is drawn from the natural world, with the speaker using images of trees, stars, and fireflies to create a sense of atmosphere and mood. The symbolism in the poem is also drawn from the natural world, with the changing of the seasons and the coming of night representing the passing of time and the inevitability of death.
The poem's main themes include the passage of time, the beauty of the natural world, and the search for meaning in life. The speaker reflects on the transience of life and the inevitability of death, but they also find solace and beauty in the natural world. The poem's title, "Let Evening Commence," suggests a sense of acceptance of the passing of time and a willingness to embrace the night.