Common Quatrains:
* AABA: The first, second, and fourth lines rhyme.
* ABAB: The first and third lines rhyme, and the second and fourth lines rhyme.
* AABB: All four lines rhyme.
* ABBA: The first and fourth lines rhyme, and the second and third lines rhyme.
Meter:
* Quatrains can be written in various meters, but iambic tetrameter (four metrical feet, each consisting of an unstressed syllable followed by a stressed syllable) is common.
Examples:
* AABA:
"The curfew tolls the knell of parting day,
The lowing herd winds slowly o'er the lea,
The ploughman homeward plods his weary way,
And leaves the world to darkness and to me." (Thomas Gray, "Elegy Written in a Country Churchyard")
* ABAB:
"The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." (Robert Frost, "Stopping by Woods on a Snowy Evening")
* AABB:
"The sun is shining bright and warm,
The birds are singing in the trees,
The world is full of joy and charm,
And everything is at its ease." (Anonymous)
* ABBA:
"My mistress' eyes are nothing like the sun;
Coral is far more red than her lips' red;
If snow be white, why then her breasts are dun;
If hairs be wires, black wires grow on her head.
I have seen roses damask'd, red and white,
But no such roses see I in her cheeks." (William Shakespeare, Sonnet 130)
Beyond these common formats:
* Other rhyme schemes exist like ABCB, ABBA, etc.
* Meter can vary from iambic pentameter to free verse.
Ultimately, the format of a quatrain is flexible and can be adapted to suit the poet's style and intentions.