The form is two hendecasyllabic verses, and a third verse beginning the same way and continuing with five additional syllables (given as the stanza's fourth verse in ancient and modern editions, and known as the Adonic or adonean line).
Using "-" for a long syllable, "u" for a short and "x" for an "anceps" (or free syllable):
- u - x - u u - u - - - u - x - u u - u - - - u - x - u u - u - - - u u - u
While Sappho used several metrical forms for her poetry, she is most famous for the Sapphic stanza. Her poems in this meter (collected in Book I of the ancient edition) ran to 330 stanzas, a significant part of her complete works (and of her surviving poetry: fragments 1-42). It is not clear if she created it or if it was already part of the Aeolic tradition; according to Marius Victorinus (Ars grammatica 6.161 Keil), it was invented by Alcaeus but then used more frequently by, and so more strongly associated with, Sappho.
Use by other poets 
A few centuries later, the Roman poet Catullus admired Sappho's work and used the Sapphic meter in two poems, Catullus 11 and Catullus 51. The latter is a rough translation of Sappho 31. Sapphics were also used by Horace in several of his Odes, including Ode 1.22:
- Integer uitae scelerisque purus
- non eget Mauris iaculis neque arcu
- nec uenenatis grauida sagittis,
- Fusce, pharetra...
- (The man who is upright in life and free
- of wickedness, he needs no Moorish spears
- nor bow nor quiver heavy with envenomed
- arrows, Fuscus...)
- So the goddess fled from her place, with awful
- Sound of feet and thunder of wings around her;
- While behind a clamour of singing women
- Severed the twilight.
Thomas Hardy chose to open his first verse collection Wessex Poems and other verses 1898 with "The Temporary the All," a poem in Sapphics, perhaps as a declaration of his skill and as an encapsulation of his personal experience.
- Change and chancefulness in my flowering youthtime,
- Set me sun by sun near to one unchosen;
- Wrought us fellowly, and despite divergence,
- Friends interblent us.
- Once, after long-drawn revel at The Mermaid,
- He to the overbearing Boanerges
- Jonson, uttered (if half of it were liquor
- Blessed be the vintage!)
Allen Ginsberg also experimented with the form:
- Red cheeked boyfriends tenderly kiss me sweet mouthed
- under Boulder coverlets winter springtime
- hug me naked laughing & telling girl friends
- gossip til autumn
Isaac Watts penned "The Day of Judgment" subtitled An Ode Attempted in English Sapphic (here are the third and fourth stanzas):
- Such shall the noise be and the wild disorder,
- (If things eternal may be like these earthly)
- Such the dire terror, when the great Archangel
- Shakes the creation,
- Tears the strong pillars of the vault of heaven,
- Breaks up old marble, the repose of princes;
- See the graves open, and the bones arising,
- Flames all around 'em!
Australian Classicist and poet John Lee wrote a Sapphic stanza about the impossibility of writing Sapphic stanzas in English:
- Making Sapphics isn't that easy, shackling
- Our reluctant language with trochees. Since you
- First begot them, songstress of Lesbos, keep them.
- I'll never write them.
(the poem exist also in Latin version).
The Australian poet John Tranter has also written a poem ("Writing in the Manner of Sappho") in two Sapphic stanzas about the difficulty of writing Sapphics in English:
- Writing Sapphics well is a tricky business.
- Lines begin and end with a pair of trochees;
- in between them dozes a dactyl, rhythm
- rising and falling,
- like a drunk asleep at a party. Ancient
- Greek — the language seemed to be made for Sapphics,
- not a worry; anyone used to English
- finds it a bastard.