Sentence topic without grammatical function

Question

From here:

このスポーツは、海の上を走る水上オートバイから足に付けたボードにホースで水を送って、ボードから出る水の強い力で空中を飛びます。
In this sport you fly through the air using the force of water ejected from a board attached to the feet. Water is sent to the board using a hose from a jet ski that runs along the surface of the sea. (Wow. I couldn't get that into just one English sentence.)

Sometimes I see a sentence where the topic appears to serve no grammatical function in the rest of the sentence. This seems to be one of those cases. Normally the topic serves as the subject or object of one of the verbs in the sentence, or sometimes it can be adverbial.

In my English translation I used "In this sport" so that the topic adverbially acts on 飛ぶ. If I'd tried to write this sentence in Japanese I'd similarly have begun with このスポーツでは. Would I be wrong to do that? Am I missing something in the way I think about topics?

Answer 1

Since this is in a formal article, I personally think this is a poorly-written sentence that has a subject-predicate mismatch. It should have been either of the following:

• このスポーツは、(略)水の力で空中を飛ぶものです。
• このスポーツでは、(略)水の力で空中を飛びます。

Japanese is a topic-prominent language, and sometimes このスポーツは空中を飛びます can be perfectly acceptable as an eel sentence, particularly in speech. For example it's perfectly fine to say ウェイクボードはジャンプするだけですがフライボードは空中を飛びます. For details, please see this and this. That said, I believe eel sentences should be avoided when you formally describe a complex idea and there is no contrast nor repetition.

---

Admittedly, there are a few native speakers who do this even in formal situations, so the level of acceptance may vary.

• (questionable) 最大の問題は予算がありません。
• (good) 最大の問題は予算がないことです。／最大の問題として予算がありません。
• (questionable) 原因は、日付をよく確認しませんでした。
• (good) 原因は、日付をよく確認しなかったことです。

Answer 2

The fact that you translate it in a natural English by "in this sport" doesn't mean that it's the correct way to interpret it. I think you already know it but I can't stress enough how important it is to differentiate "translation" and "interpretation".

Translation is basically re-writing something in another language keeping more or less the original meaning of the sentence. It doesn't have to be the equivalent, carry out the same degree of formality/politeness etc. It can be anything as long as it's coherent. Some translators completely change the meaning of some sentences just to keep a certain coherence and avoid confusion (example: jokes which are pretty hard to translate from one language to another).

Interpretation is what you think of when you see/hear something. It doesn't matter whether it's natural (or even coherent) or not.

Anyway, here while は can be translated as "in", I think to properly interpret it you should see it as being nothing more than a "subject (re-)introducer". It introduces the subject of the sentence (what is going to be talked about) and that's all. And since it's what is being talked about, it is obviously linked to a verb or adjective. But it's not linked as in "adverbially linked" but rather as in "semantically linked". It doesn't really impact how the action of the verb will be executed.

You can try removing it from the sentence:

海の上を走る水上オートバイから足に付けたボードにホースで水を送って、ボードから出る水の強い力で空中を飛びます。

It's not wrong but we don't really know what we're talking about here, even in your article where we know what the topic is, without a theme for the sentence it's a bit weird.

To sum it up, このスポーツは here is used to reintroduce an information that they brought up in a previous sentence, and make it the main subject of this new sentence. The previous sentence being in this case:

２６日、香川県坂出市の海で、水の力で空中を飛ぶスポーツをしていた４１歳の男性が亡くなりました。

Now as for このスポーツでは, it's fine. And to me in this case, で carries a nuance of limit, so では would mean something along the lines of "within". And while we're at it, I think that your translation "in this sport" would be more accurate for このスポーツでは than for このスポーツは. I would actually translate the は in your sentence by:

このスポーツは、海の上を走る水上オートバイから足に付けたボードにホースで水を送って、ボードから出る水の強い力で空中を飛びます。 : This sport consists of...

Which to me seems more accurate knowing the context.

Answer 3

A topic IS NOT necessarily the subject of the sentence. There is no equivalent of a topic in English.

According to "A Dictionary of Basic Japanese Grammar", page 21: Roughly speaking, the topic of a sentence is what the sentence is about.

You can find sentences where the topic has not syntactic function.

For example: 像は鼻が長い. Literally it means "speaking of elephants, the nose is long." But in English you would say "the nose of the elephant is long".

So このスポーツは introduces the topic of the following sentences: "Speaking about this sport". But the word "sport" will not necessarily be the subject or object or adverb of any of the sentences that follow, even though all those sentences will be about sport.