A sonnet is a highly controlled form of poetry.
It has 14 lines, each with 10 syllables in what is called iambic pentameter with alternating soft and hard beats.
There are 3 groups of 4 lines, followed by 2 lines at the end.
The rhyme scheme for each of the 4 line groups is in the style of a/b/a/b – i.e. the first and third lines rhyme and the second and the fourth.
The final 2 lines (the couplet) usually rhyme.
The following 3 sonnets show how varied the form can be and still meet all the requirements.
Shakespeare Sonnet 116
Let me not to the marriage of true minds
Admit impediments. Love is not love
Which alters when it alteration finds,
Or bends with the remover to remove.
O no! it is the ever-fixed mark
That looks on tempest and is never shaken.
It is the star to every wand’ring barque,
Whose worth’s unknown, although his height be taken.
Love’s not time’s fool, though rosy lips and cheeks
Within his bending sickle’s compass come;
Love alters not with his brief hours and weeks,
But bears it out even to the edge of doom.
If this be error and upon me proved,
I never writ, nor no one ever loved.
Andrew MacLeish The end of the world
Quite unexpectedly, as Vasserot
The armless ambidextrian was lighting
A match between his great and second toe,
And Ralph the lion was engaged in biting
The neck of Madame Sossman while the drum
Pointed, and Teeny was about to cough
In waltz-time swinging Jocko by the thumb
Quite unexpectedly the top blew off.
And there, there overhead, there, there hung over
Those thousands of white faces, those dazed eyes,
There in the starless dark, the poise, the hover,
There with vast wings across the cancelled skies,
There in the sudden blackness the black pall
Of nothing, nothing, nothing – nothing at all.
Percy Shelley Ozymandias
I met a traveller from an antique land
Who said: Two vast and trunkless legs of stone
Stand in the desert. Near them on the sand,
Half sunk, a shattered visage lies, whose frown
And wrinkled lip and sneer of cold command
Tell that its sculptor well those passions read
Which yet survive, stamped on these lifeless things,
The hand that mocked them and the heart that fed.
And on the pedastal these words appear:
“My name is Ozymandias, king of kings:
Look on my works, ye mighty, and despair!”
Nothing beside remains. Round the decay
Of that colossal wreck, boundless and bare,
The lone and level sands stretch far away.
(Yes, Shelley changes the rhyme scheme in the second part.)