> Who would you say the subject of this sentence is?

I changed the sentence. Now it can only be "I".

May I ask you why you seem to prefer to remove ambiguity from your Japanese sentences? Isn't it potentially helpful to learn of ambiguous cases?

You can add any number of sentences though, so choosing the latter solution over the former one apparently implies the former isn't desirable, hence I'm asking.

Many of the users of our sentences use sentence pairs, so even if you add multiple translations, they see only one of them. Some learners would think that that is the only possible meaning of the sentence, while others would think it's one possible translation anyway and guess it could mean something else, which is often a wrong assumption. That's why I don't like ambiguous sentences on Tatoeba. I believe the best way to learn about a ambiguous sentence is to hear or read them in a concrete context that makes it unambiguous.

Some people believe that when a Japanese sentence has no subject, the implied subject can be anything. This is simply wrong. Postpositions and verbs and adjectives often specify the meaning. Even if a single sentence can theoretically have tons of meanings, not many sentences are actually ambiguous in a real context. I think it's one of my tasks to help the learners understand whether a speaker is saying "I am" or "you are" or "she is" (you see even our talented translators make this kind of mistake), so I'm trying to avoid having sentences that can mean any of these.

Of course, it's still very difficult to write a really unambiguous sentence. There's almost always an interpretation that is unlikely but possible in some rare situation. If someone wants to add these kinds of translations, I cannot stop it, but I doubt that learners will find them useful.

Does this answer your question?

ちなみにこういう観点でいくと歌の歌詞などは最高に難しいです。
さきほど（http://tatoeba.org/eng/sentence...nt-431604）紹介した BUMP OF CHICKEN の「スノースマイル」の一節を見てみてください。

「雪が降ればいい」と　口を尖らせた
思い通りにはいかないさ
落ち葉を蹴飛ばすなよ　今にまた転ぶぞ
何で怒ってるのに　楽しそうなの？
http://www.utamap.com/showkasi.php?surl=B01797

「口を尖らせた」のは誰でしょう？ 普段のぼくなら、これは書き言葉の文体で、1人称か3人称のはずだと説明します。しかし、歌詞全体を見ると、「尖らせた」の主語は明らかに「君」だということが分かります。（そしてこの行の語り手は回想している今の「僕」で、以下3行の語り手は当時「僕」が「君」に語りかけた言葉がそのまま並んでいます。）

このような文脈があれば、歌詞や詩といったジャンルであれば、ほとんどあらゆる文に対して2人称を指しているという解釈が成り立ちうることになります。ただ、そのようなものを文脈のないところで訳として提示するのは不親切だと思うのです。学習者がこの文脈を一人で再構成できるとはとても思えませんから。

Do most users actually use sentence pairs? That seems strange to me. o.o And exactly for the reason that one sentence can have several legitimate translations. I wonder why people would limit themselves to pairs, knowing this practice can be flawed. I for one like observing varying translations... maybe I'm simply not professional enough. :>

Context is all-important, but nevertheless, I suppose one drawback is that it may obscure the fact that there is potential ambiguity at all, which may confuse the learner should they encounter that same sentence with a different meaning. Of course, if such ambiguity arises from grammatical peculiarities and every learner who is at least intermediate knows about it even if there's still a long way for them to go to master it, as I understand is the case here, then there is perhaps very little drawback at all.
I was rather more thinking about the sort of ambiguity that the general learner may not be aware of at their level, in which case I think it's really useful to draw attention to it: even when there is no context, the learner is made aware of the potential ambiguity...or not even necessarily an ambiguity per se, but sometimes a difference in translation depending on how strong the sentence sounded, for example.

I choose not to restrict myself much and add any translation I consider possible if I want to, but I stress that anyone can ask me concerning any particular sentence if they'd like to.
I guess I should explicitly say so on my profile page or something.

Tatoeba seems to officially encourage people to use sentence pairs. Have you ever downloaded a list?
If not, try downloading this list with English translations.
http://tatoeba.org/eng/sentence.../show/4039/eng

Also, remember that there are many sites and apps that use our sentences. People who visit Tatoeba.org and read comments and tags are actually minority. We're not only working for people who visit this site.

Trang wrote, "So the concept is : we gather a lot of data, try to organize it, ensure it is of good quality and make it freely accessible, downloadable and redistributable, so that anyone who has a great idea for a language learning application (or a language tool) can just focus on coding the application and rely on us to provide data of excellent quality."
http://blog.tatoeba.org/2009/11...-language.html

If someone makes use of an app that only uses a fraction of what Tatoeba can give, it's not my fault as a contributor that some things change for the worse because useful additional info is cut off.
It's a shame that sentence triplets, quadruplets etc. cannot be handled easily. o.o

Even though a sentence may have multiple translations, we still deal with reversible pairs "original - translation". There may be various scenarios of Tatoeba usage but, I think, the most common ones include searching for examples of translations and/or usage of certain words, expressions and phrases. If some phrase is potentially ambiguous, certainly it would be useful to find several alternate translations and I don't think that extra context can do any harm no matter how evident that ambiguity may be.
We should always remember that Tatoeba Corpus is being used on numerous internet resources users of which often don't even suspect about Tatoeba existence and, thus, will never come to our project for authors' comments, answers, explanations, etc. The more self-explanatory Tatoeba sentences will be, the better, I believe.
Talking about the Japanese sentence the discussion has started from, I can't say it was ambiguous. It was rather vague. Let me explain. Is this Russian sentence ambiguous: "Всю ночь не спал"? Not at all. It has only one meaning: someone unspecified stayed up all night. Who was that someone? "Он/he", "я/I", "Том/Tom", "отец Мэри/Mary's father"? This is what the context should tell us. In many languages it's very easy (and in Japanese, Tommy please correct me if I'm wrong, this is especially easy) to get such a vague sentence just by taking it out of context. And I suspect that such sentences are hardly (if at all) translatable to some languages without that context provided. So why complicate things when the solution is as simple as a couple of extra words or phrases?

Well, nice example. Such abridged sentences are, I believe, perceived by most speakers as lacking when standalone; there is a clear feeling that an element is missing, which one would expect to find in the context around the sentence.
If Japanese sentences of that sort are felt to be similarly lacking when standalone by Japanese speakers, then changes are by all means agreeable.

I don't see anything wrong with writing complete ambiguous sentences such as "Где ты сидел?" since they do not become any less valid for being ambiguous. And in this case, the translations ("Where were you sitting/did you sit?" vs "Where did you do time?") make it clear what sort of context can be expected.~

People should still keep in mind that the translation they came across may not be the only one or the best one. It's a template; you learn templates and platitudes and then deal with finer details and more intricate templates.

Does "uncertain" really mean 不安?

（私は） 将来が 不安（心配）だ。