The first idea of translation is that there are words that mean the same thing in different languages.
So, let's say summer, verano, été all mean the same thing.
A second idea, there are utterances, complete sentences, that correspond to complete sentences in another language.
A third idea: languages can be compared in what they must and can convey.
So there are concepts like number, gender, aspect, level of formality, tense, mood.
Let's take the second person. In English we have
This word does not have gender or number or level of formality. In Spanish we have
tú / Ud.
vosotros / vosotros / Uds.
There are five words, because the Spanish pronouns express three extra factors: level of formality, number (singular vs. plural), and, in the case of vosotros, gender as well.
I went can be fui / iba: The Spanish past tense is required to express an aspect, but the English is not.
Nouns have gender in Spanish, so the language decides to divide the world up rather arbitrarily into masculine and feminine things. Tables and chairs are feminine, as is the moon, but the sun is masculine.
English has gendered pronouns, but not gendered nouns in the linguistic sense, except to refer to animals or people of a certain gender. German has three genders, masculine. feminine, neuter.
[When we think of untranslatable words, we are thinking on the level of the word. Many people find this concept interesting, but I don't, because it is really just a function of the third level (languages divide things up differently and choose what to express, or not), but applied to problems of the first degree: finding equivalents for individual words. It would be rather weird if each language came up with the exact same way of carving up reality. One language has a word for the feeling of joy when something happens to your enemy, another does not. So what? That would be expected, not surprising.]
If we are still thinking on levels 1, 2, and 3, we are thinking about: synonymous words in different languages, the possibility of expressing the same idea in two different languages, and the way languages line up (or fail to line up) in what factors they can, or must, express.
Level four would be to look at the text to be translated in a holistic. What is its style, its poetics, its context? What is distinctive about it? Is it a scientific treatise, a folk ballad? What kind of Spanish is it (historically, geographically)?
The next idea (5) is to look at what kind of existing (or potential) styles exist (or could exist) in the target language. Here, again, different literatures will have different resources. Imagine translating a novel into a language in which there are no novels yet written. The the translator would essentially be inventing an entirely new discourse in the target language. Now, imagine a more "normal" situation, in which we have many available fictional discourses in the target language, from which to choose, or mix and match.
Idea 6, then, is that translation is a way of comparing, not two languages, but two systems of discourse that differ in what resources are already developed. Now we have gone from the idea of comparing two words, to the idea of comparing two distinctive literary universes.
The haiku scholar Makoto Ueda follows more or less this protocol. He first wants to define what Basho's hokku is in itself:
I believe a hokku... is a short, three phrase poem intended to charm the reader into contemplating some aspect of nature or the human condition, usually through the help of a seasonal word. I also share the view that the 17-syllable poem presents an observation in all its immediacy, before it is intellectually conceptualized.
This is sufficient. Suppose someone had a different idea of the hokku; that would be fine, took as long as it could be expressed in terms as specific as these.
The second factor is Ueda's "predilection for a certain English poetic style." He has certain ideas about what he likes in a poem written in English, and what kind of styles already existing in English come the closest to the qualities he perceives in the original. Notice he's not focussed here on how to translate words or complete utterances, or on how English and Japanese line up with each other (or differ) grammatically.