The first stanza is an exception to the rhyme pattern followed in the other stanzas. In the first stanza, the first four lines all rhyme with each other; then the fifth and seventh lines have a different rhyming sound and the sixth and eighth lines have a third rhyming sound.
The other three stanzas all follow the same rhyming pattern. The first and third lines rhyme with each other, as do the second and fourth lines. The fifth and seventh lines rhyme with each other, as do the sixth and eighth lines.
So, the rhyme pattern for the first stanza could be summarized as AAAABCBC. For the last three stanzas, the rhyme pattern could be described as ABABCDCD.
what is the significance of rhyming words?