The pattern of rhymes at the ending of each line in a poem is called a rhyme scheme. Letters (A,B,C...) are usually used to express which lines rhyme. Verses that are designated with the same letter are said to rhyme with each other. It is also known as an arrangement of rhymes in a stanza or a poem.
For easier understanding of the concept, let us take a famous nursery rhyme, written by Jane Taylor as an example.
Twinkle twinkle little star,
How I wonder what you are.
Up above the world so high
Like a diamond in the sky.
We see that the first two lines rhyme with each other (star-are); the second two lines rhyme with each other (high-sky). Let us name each line as \(A\), \(B\) depending on the words that rhyme with each other.
|Twinkle twinkle little star,|
|How I wonder what you are.||A|
|Up above the world so high,||B|
|Like a diamond in the sky.||B|
It can thus be seen that this poem follows \(AABB\) pattern.
Rhyme scheme of the poem "How to Tell Wild Animals":
|If ever you should go by chance||\(A\)|
|To jungles in the east;||B|
|And if there should to you advance||\(A\)|
|A large and tawny beast,||B|
|If he roars at you as you’re dyin’||C|
|You’ll know it is the Asian Lion...||D|
|Or if some time when roaming round,||\(A\)|
|A noble wild beast greets you,||B|
|With black stripes on a yellow ground,||\(A\)|
|Just notice if he eats you.||B|
|This simple rule may help you learn||C|
|The Bengal Tiger to discern.||C|
|If strolling forth, a beast you view,||\(A\)|
|Whose hide with spots is peppered,||B|
|As soon as he has lept on you,||\(A\)|
|You’ll know it is the Leopard.||B|
|’Twill do no good to roar with pain,||C|
|He’ll only lep and lep again.||C|
|If when you’re walking round your yard||\(A\)|
|You meet a creature there,||B|
|Who hugs you very, very hard,||\(A\)|
|Be sure it is a Bear.||B|
|If you have any doubts, I guess||C|
|He’ll give you just one more caress.||C|
|Though to distinguish beasts of prey||\(A\)|
|A novice might nonplus,||B|
|The Crocodile you always may||\(A\)|
|Tell from the Hyena thus:||B|
|Hyenas come with merry smiles;||C|
|But if they weep they’re Crocodiles.||D|
|The true Chameleon is small,||\(A\)|
|A lizard sort of thing;||B|
|He hasn’t any ears at all,||\(A\)|
|And not a single wing.||B|
|If there is nothing on the tree,||C|
|’Tis the chameleon you see.||C|
It can thus be seen that this poem follows \(ABABCD\) pattern in the first stanza and \(ABABCC\) in the rest of the stanzas.