Why would you use な for そう forms of い adjectives?


I am just now really diving into adjectives and how they work in Japanese. It
was to my surprise that I heard 『楽{たの}しいそうなお祭{まつ}りね』 being used. Does the そう
usage require な even for い adjectives?




There are two things I would like to do as part of the answer to your
question.

First, you may not have been aware that there was a mistake in your sentence.
I will address that first.

You wrote:

> 楽{たの}しいそう

It should be:

> 楽{たの}しそう

For the formation of the そうだ grammar is as follows:

  * Vmasu + そうだ
  * adj(i/na) stem + そうだ

Examples:

> 話しそう (verb)  
>  楽しそう (i adjective)  
>  静かそう (na adjective)

Source: A Dictionary of Basic Japanese Grammar (See below)

* * *

Now for the question you acked. According to [A Dictionary of Basic Japanese
Grammar](https://rads.stackoverflow.com/amzn/click/4789004546) (Seiichi Makino
and Michio Tsutsui):

> そうだ is a な-type adjective; The prenominal form is そうな. Examples:
>

>> 高そうな車  
>  taka souna kuruma  
>  (A car which looks espensive (= an expensive looking car))
>>

>> 雨が降りそうな空  
>  ame ga furi souna sora  
>  (lit. the sky which looks like it will bring rain)

So to directly answer your question:

> Does the そう usage require な even for い adjectives?

The answer is yes. Note that most of the time, you will find this formation at
the end of a sentence requiring it to end with だ/です. However, if you plan on
using this grammar as an adjective (i.e. you mean to use it to modify a noun),
you should treat is as a na-type adjective.

Note: I included a link to the amazon listing of the book I used for my
source. If you plan to purchase it, look around. I have definitely seen it
sell for less.




There are two things I would like to do as part of the answer to your
question.

First, you may not have been aware that there was a mistake in your sentence.
I will address that first.

You wrote:

> 楽{たの}しいそう

It should be:

> 楽{たの}しそう

For the formation of the そうだ grammar is as follows:

  * Vmasu + そうだ
  * adj(i/na) stem + そうだ

Examples:

> 話しそう (verb)  
>  楽しそう (i adjective)  
>  静かそう (na adjective)

Source: A Dictionary of Basic Japanese Grammar (See below)

* * *

Now for the question you acked. According to [A Dictionary of Basic Japanese
Grammar](https://rads.stackoverflow.com/amzn/click/4789004546) (Seiichi Makino
and Michio Tsutsui):

> そうだ is a な-type adjective; The prenominal form is そうな. Examples:
>

>> 高そうな車  
>  taka souna kuruma  
>  (A car which looks espensive (= an expensive looking car))
>>

>> 雨が降りそうな空  
>  ame ga furi souna sora  
>  (lit. the sky which looks like it will bring rain)

So to directly answer your question:

> Does the そう usage require な even for い adjectives?

The answer is yes. Note that most of the time, you will find this formation at
the end of a sentence requiring it to end with だ/です. However, if you plan on
using this grammar as an adjective (i.e. you mean to use it to modify a noun),
you should treat is as a na-type adjective.

Note: I included a link to the amazon listing of the book I used for my
source. If you plan to purchase it, look around. I have definitely seen it
sell for less.

