It seems that 渡る is categorized as 自動詞 (intransitive verb), yet it is frequently used with を. Why?


Jisho says [渡る is an intransitive
verb](http://jisho.org/words?jap=%E6%B8%A1%E3%82%8B&eng=&dict=edict), and ALC
says [it is sometimes 自動 and sometimes
他動](http://eow.alc.co.jp/search?q=%E6%B8%A1%E3%82%8B).

In either case, the particle を can be used. What's going on here?




This is one of those instances where we as English speakers encounter a term
and assume that it matches its English equivalent perfectly, but actually the
distinction between transitive and intransitive verbs is a little bit fuzzier
than you may have been led to believe. As such this answer may not be very
intuitive.

The basic point is that taking a direct object _doesn't necessarily mean a
verb is transitive_. In this [dictionary entry for
他動詞](http://www.weblio.jp/content/%E4%BB%96%E5%8B%95%E8%A9%9E):

>
> 〔英語などでは目的語をとり、主語・目的語を転換して受け身表現にすることができるなど、他動詞とはっきり認定することができる。しかし、日本語では、目的語の表示が必ずしも明らかでなく、また、目的語をとらない「泣く」が「子供に泣かれる」のように受け身に使われたりして、自動詞と他動詞の区別を明確にしにくい面がある〕

And the [entry for
自動詞](http://www.weblio.jp/content/%E8%87%AA%E5%8B%95%E8%A9%9E):

> 西欧語では目的語をとらない・とるなど、自他の別がはっきりと表れるが、日本語では必ずしも明確でない。

Basically it's saying that the line is fuzzy in Japanese while there are some
clear rules in Western languages.

So what about 渡る, specifically? Why does this fall into that fuzzy category?

Check out [this
discussion](http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1037449360).
Examining the definitions a little closer we see that for a verb to be
transitive it must be on operation _on_ that object. When you cook rice you
are acting on the rice. When you kick a ball you are acting on the ball. But
when you cross a bridge, are you acting on the bridge? Are you doing something
to it? Not really; the bridge just happens to be where you're walking.

Another way to look at it is to say that the を isn't marking an _object_ but a
_path_. You can find the same kind of misunderstanding with 歩く. When you say
道を歩く, does 歩く become a transitive verb? No, and [this
site](http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1268761667) can
support that. At the end of the day the operating phrase seems to be
"自他の対応がない."

