Translation guide
Expresses that something does not appear to be the case based on evidence or impression. Japanese uses several constructions depending on the type of evidence (direct observation, hearsay, inference) and the part of speech of the word it attaches to.
The speaker judges from what they see or perceive that something is not the case.
It doesn't look like it's going to rain.
He doesn't seem like he's coming.
This dish doesn't look tasty.
Literally 'does not look like'. Used when the visual evidence contradicts an assumption. More objective than ～そうにない.
He doesn't look tired.
The speaker reports that according to what they've heard, something is not the case.
Used to report hearsay. ～ないそうだ is more common in spoken Japanese, while ～ないということだ is slightly more formal.
I heard it's not going to rain tomorrow.
I heard that he's not coming.
Expresses conjecture based on indirect evidence or hearsay. Less certain than ～そうだ.
It seems he's not coming (from what I've heard).
The speaker deduces that something is not the case based on reasoning.
Expresses a subjective inference based on evidence. ～ないみたいだ is more colloquial. Both are very common.
It seems he hasn't arrived yet.
This problem doesn't seem difficult.
Strongly expresses that something cannot be the case based on logic or expectation. 'There's no way that...'
He can't possibly do such a thing. (It doesn't seem possible.)
To say that something does not seem to be a certain noun or na-adjective quality.
The negative form of ～そうだ for nouns and na-adjectives. Used when something doesn't appear to be X.
He doesn't seem to be a student.
This room doesn't seem quiet.
Use そうにない with verbs and i-adjectives (e.g., 降りそうにない, 高そうにない). Use ではなさそうだ with nouns and na-adjectives (e.g., 学生ではなさそうだ, 静かではなさそうだ).
Do not directly translate 'does not seem' as 見えない in most contexts. 見えない means 'cannot see' and is only used for visual appearance. Use the patterns above for general impressions.