Hello. You did not show the poem to which this question refers. Thus, it is not possible to read the poem and analyze the development of the theme. However, I will try to help you in the best possible way.
In a poem the themes are developed through the use of literary devices. The most common is that this theme is presented through the rhyme or other sound devices, since these devices highlight a specific element of the text, usually the theme. However, symbolism is also used to represent concepts that emphasize the theme of the poem.
