The に particle and potential form


これはアメリカ人にも読める日本語の本です。

I received this sentence as an example of に being used with potential form in
a passive sense, but even though the person said they were Japanese (online) I
have never seen anything like this ever.

What is this grammar point? Can I have any other examples? If it is incorrect,
how would you say "Y can be done by X" where it is both potential and passive?




Usually, when people say "passive" in the context of Japanese, they're
describing verb forms that have the suffix 〜(ら)れる attached. Take a look at the
following examples, taken from the section on passives in Shibatani's _The
Languages of Japan_ , p.318:

> 友達【ともだち】が太郎【たろう】を殴る【なぐる】。 _(non-passive version)_  
>  "The friend **hits** Taro."
>
> 太郎は友達に殴 **られ** た。 _(passive version)_  
>  "Taro **was hit by** a friend."

This form can express a number of things, including _passive_ , _potential_ ,
and less commonly _honorific_ and _spontaneous_ meanings. For details on this
form, please see your textbook; in this answer, I'm going to concentrate on
the form you asked about.

Since your sentence doesn't contain 〜(ら)れる, I would say it's not actually
passive. You could argue otherwise, and you could translate it with the
passive voice in English if you like, but I think it's active in Japanese.

In your sentence, に is expressing who is capable of reading the book. It
changes the statement from a general one to a statement about Americans. (But
since there's a も, it means Americans _as well_ [as Japanese], or _even_
Americans.)

Take a look at the following examples from [Shibatani's 1999 paper on dative
constructions](http://www.ideals.illinois.edu/bitstream/handle/2142/9678/SLS1999v29.2-06Shibatani.pdf?sequence=2),
pp.63-64:

> a. 日本語が話せる。  
>  "Japanese can be spoken."
>
> b. ハワイで(は)日本語が話せる。  
>  "In Hawai'i Japanese can be spoken."
>
> c. ケンに(は)日本語が話せる。  
>  "Ken can speak Japanese / Ken can be spoken Japanese to;  
>  (lit) With respect to Ken, it is true that Japanese can be spoken"

Here's what Shibatani write about these examples:

> Consider a Japanese potential expression like [a]. It is not true that
> Japanese can be spoken anywhere or by anyone. This statement thus **needs to
> be confined to a particular domain**. This can be done either by providing a
> location in which Japanese can be spoken, as in [b], or **a person who can
> realize the potential state** , as in [c]. _(emphasis added)_

The statement you're asking about is similar to [c], except that it's been
turned into a relative clause. Here's a non-relative version, with the head
noun phrase 日本語の本 inserted with a が-role:

> アメリカ人にも（日本語の本が）読める  
>  "A Japanese book is readable by { even Americans / Americans, too }"

This noun phrase is pulled out, and it's turned into a relative clause:

> （アメリカ人にも読める）日本語の本  
>  "A Japanese book that { even Americans can read / Americans can read, too
> }"

This makes a single noun phrase which is placed inside the larger sentence
これは〜です, which of course means "This is 〜 (polite)":

> これは（（アメリカ人にも読める）日本語の本）です。  
>  "This is a Japanese book that { even Americans can read / Americans can
> read, too } (polite)"

And with that, we've put your sentence back together.




Usually, when people say "passive" in the context of Japanese, they're
describing verb forms that have the suffix 〜(ら)れる attached. Take a look at the
following examples, taken from the section on passives in Shibatani's _The
Languages of Japan_ , p.318:

> 友達【ともだち】が太郎【たろう】を殴る【なぐる】。 _(non-passive version)_  
>  "The friend **hits** Taro."
>
> 太郎は友達に殴 **られ** た。 _(passive version)_  
>  "Taro **was hit by** a friend."

This form can express a number of things, including _passive_ , _potential_ ,
and less commonly _honorific_ and _spontaneous_ meanings. For details on this
form, please see your textbook; in this answer, I'm going to concentrate on
the form you asked about.

Since your sentence doesn't contain 〜(ら)れる, I would say it's not actually
passive. You could argue otherwise, and you could translate it with the
passive voice in English if you like, but I think it's active in Japanese.

In your sentence, に is expressing who is capable of reading the book. It
changes the statement from a general one to a statement about Americans. (But
since there's a も, it means Americans _as well_ [as Japanese], or _even_
Americans.)

Take a look at the following examples from [Shibatani's 1999 paper on dative
constructions](http://www.ideals.illinois.edu/bitstream/handle/2142/9678/SLS1999v29.2-06Shibatani.pdf?sequence=2),
pp.63-64:

> a. 日本語が話せる。  
>  "Japanese can be spoken."
>
> b. ハワイで(は)日本語が話せる。  
>  "In Hawai'i Japanese can be spoken."
>
> c. ケンに(は)日本語が話せる。  
>  "Ken can speak Japanese / Ken can be spoken Japanese to;  
>  (lit) With respect to Ken, it is true that Japanese can be spoken"

Here's what Shibatani write about these examples:

> Consider a Japanese potential expression like [a]. It is not true that
> Japanese can be spoken anywhere or by anyone. This statement thus **needs to
> be confined to a particular domain**. This can be done either by providing a
> location in which Japanese can be spoken, as in [b], or **a person who can
> realize the potential state** , as in [c]. _(emphasis added)_

The statement you're asking about is similar to [c], except that it's been
turned into a relative clause. Here's a non-relative version, with the head
noun phrase 日本語の本 inserted with a が-role:

> アメリカ人にも（日本語の本が）読める  
>  "A Japanese book is readable by { even Americans / Americans, too }"

This noun phrase is pulled out, and it's turned into a relative clause:

> （アメリカ人にも読める）日本語の本  
>  "A Japanese book that { even Americans can read / Americans can read, too
> }"

This makes a single noun phrase which is placed inside the larger sentence
これは〜です, which of course means "This is 〜 (polite)":

> これは（（アメリカ人にも読める）日本語の本）です。  
>  "This is a Japanese book that { even Americans can read / Americans can
> read, too } (polite)"

And with that, we've put your sentence back together.

