What is a Sonnet?

Sonnets are poems of expressive ideas or thoughts that can take a number of different forms, but always have two things in common.

1. All sonnets have fourteen lines

The fourteen lines of a sonnet are made up of one of a number of different rhyme patterns. For example, a sonnet can be divided into two sections, each section having its own rhyme pattern. This could be an eight-line section (called an octet), followed by a six-line section (called a sestet) – the form used by the Italian poet, Petrarch, the most famous sonnet writer apart from Shakespeare. It’s known as the Petrarchan Sonnet or the Italian Sonnet.

Sonnet can also be divided into three four-line sections (called quatrains), followed by a two-line section (called a couplet). This is the form Shakespeare used and the form has become known as the Shakespearean Sonnet or the Elizabethan Sonnet.

2. All sonnets are written in iambic pentameter

Iambic pentameter refers to the structure of the line. Iambic refers to the name of the foot, which is composed of a weaker syllable followed by an accented syllable.  For example, the word away has two syllables with a weak stress on the first, ‘a’, and a strong stress on the second, ‘way’. The word constitutes a foot or an iambus. Pentameter simply refers to the number of feet, in the case of the sonnet, five. All sonnets use iambic pentameter, and almost all the lines in Shakespeare’s plays are written in iambic pentameter as well. Read our in-depth guide to iambic pentameter.

The rhyming pattern of a Shakespearean sonnet

The Shakespearean sonnet expresses a single idea, but the division into three quatrains and one couplet allows the poet to switch the focus, dealing with a different aspect of the idea in each section. (We go into a lot more detail on this in our guide on how to write a sonnet.)

In a Shakespearean sonnet the quatrain patterns look like this: ABAB CDCD EFEF and the couplet is GG. All the words ending the lines with the same letter rhyme with each other. All Shakespearean sonnets follow this pattern. Here is Shakespeare’s sonnet 116 where he writes about love:

First Quotrain

Let me not to the marriage of true minds -A

Admit impediments. Love is not love – B

Which alters when it alteration finds, – A

Or bends with the remover to remove: – B

Second Quotrain

Oh, no! it is an ever-fixéd mark, – C

That looks on tempests and is never shaken; D

It is the star to every wandering bark, -C

Whose worth’s unknown, although his height be taken. – D

Third Quotrain

Love’s not time’s fool, though rosy lips and cheeks – E

Within his bending sickle’s compass come’ – F

Love alters not with his brief hours and weeks, – E

But bears it out even to the edge of doom. – F

Couplet

If this be error and upon me proved, – G

I never writ, nor no man ever loved. – G

The first quatrain announces that love is perfect and can’t be affected by anything. The second quatrain elaborates on that, showing that love is something absolutely stable in a tumultuous world. The third quatrain switches the focus to time and suggests that love lasts forever. The couplet is a final summing up in which the poet stakes his career on the truth of what he’s revealed about love.

And that’s the answer to the question “what is a sonnet?“!

If you want to know more about sonnets check out our other sonnet resources:

• Read about the history of the sonnet
• Discover sonnet examples from different poets
• Read Shakespeare sonnets in modern English
• Download ebook of all 154 Shakespeare sonnets in modern English