Adverbial “~ku”（〜く）form of Japanese i-adjectives (and challenges of translating them)

Compared to English, I feel that Japanese is a grammatically pure language, meaning that there are less complex grammar rules, and those rules can be used more freely without becoming ungrammatical or awkward.

For example, Japanese has much fewer verb tenses than English, and factors such as the subject are not taken into account when conjugating. There is also no plural form (except for a few rare exceptions), and no articles such as “the” and “a” that appear in many Latin-based languages. Finally, word order is a bit more flexible in Japanese than English.

For sure, mastering Japanese particles can take some effort, but overall I think Japanese grammar is significantly easier than English. (However, for someone who speaks English as a native language, Japanese grammar can still pose quite a challenge, hence the need for blogs like this and many other resources).

One nice thing about Japanese is that it’s really easy to make an adverb out of an i-adjective. As a quick refresher, an adverb is something which modifies a verb, like “quickly” (that can be applied to the verb “run”). Adverbs can also modify adjectives or other adverbs. Adjectives, on the other hand, describe nouns (ex: “the red car”)

But let’s get back to how adverbs can be made from verbs in Japanese. For example, if we take the verb かわいい (cute) and replace the last い with a く we get かわいく, which is effectively the adverbial form. But how would you express this in English? You could use the adverb form of “cute”, which is “cutely”, but while that does convey the meaning I think the word “cutely” is not used very often and may sound a little unnatural. So we could just say “in a cute way”.

It turns out that Japanese adverbs will often not match up perfectly with their English counterparts. To give another example, let’s look at this sentence:

• ライオンは口を大きく開いた (raion wa kuchi ga ookiku hiraita)

The adverb here is 大きく which comes from 大きい, the latter being an adjective that means “big”. So what is the adverbial form of “big”? “Bigly” seems to technically be a word, but I’ve rarely heard it used before. However, the word “big” is also technically an adverb (ex: “Don’t write so big”), so let’s try to translate it using that:

• The lion opened its mouth big.

Surely you’ll agree this sounds awkward. If you think about it long enough (a thesaurus may help speed up the process), you’ll think of words like “widely” or “largely” which can give a natural translation.

Here’s another example:

• 彼は首を軽く振った (kare wa kubi wo karuku futta)

Whereas the lion example may have been easy to understand, this example may be a little cryptic. After all, 軽く is technically “lightly”, but “shaking his head lightly” sounds a little odd. However, if you try the word “slightly” you’ll find it makes more sense and would make a reasonable translation (there are other ways though).

• 犯人は大きく叫んだ (hannin wa ookiku sakenda)

Here we see the same adverb that was used two examples ago, 大きく, which we had decided could be translated as “widely” or “largely”. Yet here thinking in terms of “screamed widely” or “screamed largely” doesn’t really make much sense. The trick in this case is to know that the volume of sounds in Japanese is often described with words like 小さい and 大きい. Therefore, a reasonable translation would be:

• The criminal screamed loudly.

Once you learn to get the feel of how adverbs are used in Japanese and to visualize how they act on certain verbs, you’ll begin to understand what they mean in context without having to translate to English in your head. Having said that, for those doing translations to English––whether it is as an exercise to confirm your understanding, or to produce a text that others can use––it’s good to be able to learn how to transform these adverbs into natural English. Keep in mind, when translating you don’t have to go word-by-word; for instance, you could consider translating the last example above as “The criminal screamed at the top of his lungs” (as long as you are sure the “he” pronoun is appropriate), or maybe even omit the adverb altogether (using the reasoning that “screaming” implies “loudly”).