Poetry evokes images of sonnets. Elizabeth Barrett Browning, William Shakespeare and countless other poets have given the sonnet in English poetry the highest respected and widest recognition of any poetry familiar to English speakers.
Do you recognize, "How do I love thee? Let me count the ways"? There are many famous sonnets. Sonnets are most commonly love poems, though they can be used in other contexts too.
Sonnets originated in Italy. It is much easier to make rhymes in Italian, but this hasn't stopped the sonnet from remaining one of English's favorite types of poetry.
Sonnets usually take one of two forms, Shakespearean and Petrarchan. They have 14 lines and have a rhyming scheme that varies depending on what type of sonnet it is.
A sonnet begins with a set of questions or statements that is then resolved or answered in the last six lines. This change or answer is called the "turn".
Shakespearean (English) sonnets, as they are called, usually have a rhyme scheme of abab cdcd efef gg. Shakespearean sonnets have three four line groupings (quatrains) followed by a two line grouping (a couplet).
Petrarchan (Italian) sonnets have an eight line grouping (an octave) followed by a six line grouping (a sestet). The first eight lines have the rhyme-scheme of abbaabba, then the last six lines take the form of cdecde, cdccdc or cdedce.
Here is a classic example of a sonnet:
Not marble, nor the gilded monument,
Of Princes shall out-live this powerful rhyme,
But you shall shine more bright in these contents
Than unswept stone, besmeer'd with sluttish time.
When wasteful war shall Statues overturn,
And broils root out the work of masonry,
Nor Mars his sword, nor wars quick fire shall burn:
The living record of your memory.
'Gainst death, and all oblivious enmity
Shall you pace forth, your praise shall still find room,
Even in the eyes of all posterity
That wear this world out to the ending doom.
So 'til the judgment that your self arise,
You live in this and swell in lovers eyes.
(William Shakespeare, Sonnet 55)
Sonnets can be a challenging a beautiful form to master. Don't feel as though you need to comply with a fixed set of rules when writing sonnets. This is a living poetry form, and will likely change in the years to come.