〜そうだ (様態) / 〜そうに / 〜そうな
Looks like 〜そうだ (conjecture)
Meaning
Visual conjecture based on appearance — "looks like ~ / seems about to ~". Based on what you directly observe (not hearsay).
Formation
verb: [stem (drop ます)] + そうだ (降りそう) · i-adj: drop い + そうだ (美味しそう) · na-adj stem + そうだ (静かそう) · いい→よさそう、ない→なさそう
Notes
DIFFERENT from hearsay そうだ (which uses plain form). This そう uses the STEM. For "looks delicious but..." use 〜そうに+verb: 美味しそうに食べている ("eating as if it's tasty"). Negative: 〜そうもない/〜なさそう ("doesn't look like ~").
Examples
このケーキ、とても美味（おい）しそうですね。
This cake looks really delicious, doesn't it.
Breakdown
空（そら）が暗（くら）くなって、雨（あめ）が降（ふ）りそうです。
The sky is getting dark; it looks like it's going to rain.
Breakdown
この問題（もんだい）は難（むずか）しそうです。
This problem looks difficult.
Breakdown
子供（こども）達（たち）が楽（たの）しそうに遊（あそ）んでいます。
The children are playing, looking like they're having fun. (そうに + verb)
Breakdown
この本（ほん）は面白（おもしろ）くなりそうです。
This book looks like it's going to get interesting.
Breakdown
彼（かれ）は元気（げんき）そうですね。
He looks well/energetic. (na-adj stem + そう)
Breakdown
⚠️ Often confused with
〜そうだ (伝聞)
I heard that 〜そうだ (hearsay)
Hearsay — "I heard that ~ / they say that ~". Reports information obtained from another so...
〜らしい
Apparently / seems 〜らしい
Conjecture based on some evidence or hearsay — "apparently ~ / I hear that ~ / it seems ~"...
〜みたいだ / 〜みたいな / 〜みたいに
Looks like / seems 〜みたいだ
Conjecture based on appearance or impression — "it looks like ~ / it seems ~". More casual...
〜ようだ / 〜ような / 〜ように
Appears / seems 〜ようだ
Conjecture or resemblance — "it appears that ~ / it seems ~ / like ~". More formal than み...
〜かもしれない
Might / perhaps 〜かもしれない
Expresses possibility — "might / perhaps / may". Indicates something is possible but not c...
〜はずだ / 〜はずです
Should be 〜はずだ (expectation)
A strong expectation based on logic or evidence — "should be ~ / ought to ~ / is supposed...
〜はずがない / 〜はずありません
Cannot be / no way 〜はずがない
Strong denial of possibility — "there's no way ~ / it cannot be that ~ / impossible". The...
〜に違いない
Must be 〜に違いない
A confident inference — "must be ~", "I am sure ~".
〜おそれがある
There is a risk that 〜おそれがある
"There is a risk / danger that ~".
〜かねない
Might well 〜かねない
"Might well ~", "could easily end up ~" — of a feared outcome.