Poetry is hard to define, but one of the common guides for what is “good” poetry, is conformity to tradition: does this poem follow the forms of Latin verse? Does that poem fit the structure of Shakespearean sonnets? Does this tanka reference the season and have a metaphysical shift in the middle? And such fitting of a time-honoured pattern while retaining fluidity and voice would seem a satisfying goal. However, these verse-forms might have a structure built on sand.
There are many supposed rules of writing haiku; potentially as many as there are poets and academics reading haiku. However, the rule that is likely to be familiar to most casual readers is line length: a haiku has a 5-7-5 structure. For example:
Scours out my very soul.
This coffee is strong.
A first line of five syllables, a second of seven, and a third of five. At least it does if you read “very” as two syllables.
This difference in counting becomes more stark when one considers that haiku is a Japanese verse-form. Thus, the line length is traditionally measured in kanji rather than syllables. With kanji having a closer association to words than an English syllabic unit does, this allows more words for your five units.
The density can be still higher once words that are formed of several kanji are considered: for example, a two-unit word might also add the meaning of two single-unit words. While using parts of a word to suggest meaning is a tool of the English-writing poet as well, they lack the same ability for every unit to have a meaning.
The same issue of verse-forms being a product of the language around them can be seen in alliterative verse. Modern British English developed from Germanic languages, so one might expect it would fit the Germanic verse-forms. However, the pronunciation has changed over the centuries: the density of particular letters/sounds at the start of words has altered, making certain alliterations easier/harder. While it isn’t as great a difference as with haiku, this change in what can fit the form constrains the poet’s ability to avoid repetitive patterns.
This is not to say it cannot be done. Whether as an intellectual exercise or a felicity of language, the verse-forms of one language can be used to create poems in another.
However, it does indicate that – even ignoring questions of which rules are due to the preferences of a society rather than strictly those of form – moving a verse-form from one language to another is likely to be assigning the labels within rules to the closest approximation anyway; the concept of, for example, a “correct” haiku in English rests on a set of assumptions about what is and isn’t a relevant change.
Do you strive to meet all the rules of a form created in another language? Do you consider conforming to the tastes of the creating culture to be different from conforming to the rules of structure?