Each of these poetic forms has something in common with at least one other form.
First, the haiku, an old Japanese form of poem, is made up of three lines with a set number of syllables per line. The pattern of syllables is 5-7-5: the first line has five syllables, the second line has seven, and the third has five. There is no rhyme scheme. This means that the last word of each line does not rhyme with the end of another line. For example, the 17th Century poet Basho wrote the following:
Now the swinging bridge (5)
Is quieted with creepers… (7)
Like our tendrilled life. (5)
Note that the number at the end of each line indicates the number of syllables in that line. There is no rhyme at the end of any of the lines.
The cinquain is based upon the haiku and tanka forms (both Japanese), but has its own syllabic pattern. The syllabic pattern used by the poet credit with developing what is now called the American cinquain (Adelaide Crapsey) is 2-4-6-8-2. Unlike the haiku and tanka, the cinquain is...
...a stanza of five lines of accentual-syllabic verse.
The accented syllables were set up with a pattern of stresses: 1-2-3-4-1.
Some resource materials define classic cinquains as solely iambic, but that is not necessarily so.
Iambic is defined as...
...a lightly stressed syllable followed by a heavily stressed syllable.
As an example, New York is said with the stress on "York." The word (or in poetry in might be a syllable) that is stressed is not the first, but the second. If we were showing how it was stressed just for the sake of exemplifying the word, we might write it as:
The mark before "YORK" is an accent mark. The American cinquain has a syllabic pattern that it follows, but also one of meter. Meter is defined as...
...varying pattern of stressed syllables alternating with syllables of less stress.
However, similar to the haiku, there is no rhyme employed.
The sonnet form originated in Italy, but was introduced into England by Sir Thomas Wyatt. Like the Italian form, the Shakespearean or English sonnet has fourteen lines and a particular meter and rhyme scheme. It is often referred to as the Shakespearean sonnet because William Shakespeare used this sonnet form a great deal, writing 154 of them. Shakespeare placed the stress on every other syllable, using what is called iambic pentameter (10 syllables per line, with a stress on every other syllable). Unlike the haiku and cinquain (that both use only syllabic patterns), the sonnet has end rhyme, so that there is a pattern followed that dictates how the last word of each line will rhyme with other lines. For example, the Shakespearean sonnet form uses this rhyme scheme:
abab cdcd efef gg
This means that the first and third line will rhyme (a) and the second and fourth line will rhyme (b), and so on. In Shakespeare's Sonnet 29, look at the pattern of rhyme. In the first line, note below the syllables that are accented—every other one...
When 'in dis-'grace with 'for-tune 'and men's 'eyes
A sonnet is much harder to write than a haiku or cinquain.
A limerick uses meter and rhyme, providing the poem with a distinctive lilting rhythm. A limerick is...
...light verse consisting of a stanza of five lines, rhyming aabba...
It also has a rhythm easily identifiable: 3-3-2-2-3. See Laura Black's limerick:
There once was a man from Peru,
Who dreamed of eating his shoe...