Line 1: 5 syllables
Line 2: 7 syllables
Line 3: 5 syllables
Line 4: 7 syllables
Line 5: 7 syllables
Here is a famous tanka written by a Japanese poet from 850 AD named Ono No Komachi.
The colour of the cherry blossom
Has faded in vain
In the long rain
While in idle thoughts
I have spent my life.
Here is Great Blue Heron by Thomas Martin:
I must tell you this bird:
long, thin legs, sharp beak
wading in a dappled stream
grayish blue, at home in Cypress
Curving skyward through Spanish moss.
For more information on how to write a tanka, visit http://www.wikihow.com/Write-a-Tanka-Poem.