what are the key characteristics of a refrain in poetry?

Here is a famous poem that has two refrains:

https://www.poets.org/poetsorg/poem/do-not-go-gentle-good-night
Read it aloud. Do you hear them?

https://literarydevices.net/refrain/

The key characteristics of a refrain in poetry are repetition and a recurring pattern. A refrain is a line, phrase, or group of lines that appears at regular intervals throughout a poem. It serves as a chorus, echoing and reinforcing an idea or theme. To identify the refrain in a poem, follow these steps:

1. Read the poem: Start by reading the entire poem to understand its overall structure and meaning.

2. Look for repetition: Pay attention to any lines or phrases that repeat multiple times within the poem. These repeated words or lines are likely the refrain.

3. Observe the pattern: Note the regularity and placement of the refrain. It may appear at the end of each stanza or at specific intervals throughout the poem.

4. Analyze the purpose: Consider the meaning and function of the refrain. How does it contribute to the overall theme or message of the poem? Does it emphasize a particular sentiment, evoke a certain mood, or enhance the rhythm of the poem?

By closely examining the poem and identifying repeated lines or phrases, you can discern the key characteristics of the refrain and delve into its significance within the poem.