Nothing Gold can stay

This poem is made up of four rhyming couplets (two lines that rhyme and complete a thought). What is the relationship between the lines in each couplet?

Each couplet has a line about hope contrasted by a line that suggests disappointment.

Each couplet has a line about community contrasted by a line about loneliness.

Each couplet has a line about nature contrasted by a line about humanmade artifacts.

The relationship between the lines in each couplet is one of contrast, with the first line expressing a fleeting, hopeful or positive sentiment, while the second line expresses a more permanent, disappointing or negative sentiment. This creates a sense of impermanence and the inevitability of change.