What's the difference between そうな/に (sou na/ni) and ような/に (you na/ni)?


I'm a beginner in Japanese.

I know ように can mean "as", "so", "like", and よう can mean "look like". And I
know that そう can mean "seem like", "that way", "or such", but there are too
many possible combinations similar to よう.

In another
[post](https://japanese.stackexchange.com/questions/16312/difference-
between-%E3%81%9D%E3%81%86%E3%81%A7%E3%81%99-%E3%82%88%E3%81%86%E3%81%A7%E3%81%99-and-%E3%82%89%E3%81%97%E3%81%84%E3%81%A7%E3%81%99)
the difference was explained for そうだ and ようだ. Here I'm asking that can you
explain what そう means for the other scenarios like そうに/な (compared to よう).

For example in the following sentence:

> 優{やさ}しそうなご両親{りようしん}でしたね  
>  "They looked like very kind parents."

What is the difference from よう in this example or other possible combinations?




～そうな is generally used in a context of "seems like" based on appearances.

～ような is generally used when you're talking about a resemblance to something.
In other words, ～ような is more directly related to the English concept of a
simile, _A like a B._

For example:

[code]

    彼女は優しそうな人です。
    
[/code]

"She seems like a nice person."

[code]

    彼女はメイドのような人です。
    
[/code]

"She looks like a maid."

[code]

    あのケーキは美味しそうです。
    
[/code]

"That cake looks delicious."

[code]

    あのケーキは雲のようにふわふわです。
    
[/code]

"That cake is fluffy like a cloud."

As you can see, the difference is subtle, but important.

In both cases, the difference of na/ni comes down to adjectival vs adverbial
forms.

そうに～ Would be something along the lines of "seemingly."

Whereas ように～ Still translates as "...like a..." in English, as English has no
real equivalent adverbial form.

You can think of it like this: when it's ～な it's always going to expect a noun
to modify. When it's ～に it's going to expect a verb to modify:

[code]

    鳥のようなすがた
    
[/code]

"looks like/shaped like a bird"

[code]

    鳥のように飛んだ
    
[/code]

"flew like a bird"

[code]

    転びそうな建物
    
[/code]

"A building that looks like it'd fall over"

[code]

    建物は転びそうにゆらゆらした
    
[/code]

"The building swayed as though it'd fall over"




～そうな is generally used in a context of "seems like" based on appearances.

～ような is generally used when you're talking about a resemblance to something.
In other words, ～ような is more directly related to the English concept of a
simile, _A like a B._

For example:

[code]

    彼女は優しそうな人です。
    
[/code]

"She seems like a nice person."

[code]

    彼女はメイドのような人です。
    
[/code]

"She looks like a maid."

[code]

    あのケーキは美味しそうです。
    
[/code]

"That cake looks delicious."

[code]

    あのケーキは雲のようにふわふわです。
    
[/code]

"That cake is fluffy like a cloud."

As you can see, the difference is subtle, but important.

In both cases, the difference of na/ni comes down to adjectival vs adverbial
forms.

そうに～ Would be something along the lines of "seemingly."

Whereas ように～ Still translates as "...like a..." in English, as English has no
real equivalent adverbial form.

You can think of it like this: when it's ～な it's always going to expect a noun
to modify. When it's ～に it's going to expect a verb to modify:

[code]

    鳥のようなすがた
    
[/code]

"looks like/shaped like a bird"

[code]

    鳥のように飛んだ
    
[/code]

"flew like a bird"

[code]

    転びそうな建物
    
[/code]

"A building that looks like it'd fall over"

[code]

    建物は転びそうにゆらゆらした
    
[/code]

"The building swayed as though it'd fall over"

