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

Question

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 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?

Answer 1

～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:

彼女は優しそうな人です。

"She seems like a nice person."

彼女はメイドのような人です。

"She looks like a maid."

あのケーキは美味しそうです。

"That cake looks delicious."

あのケーキは雲のようにふわふわです。

"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:

鳥のようなすがた

"looks like/shaped like a bird"

鳥のように飛んだ

"flew like a bird"

転びそうな建物

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

建物は転びそうにゆらゆらした

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