Examples
Meaning
These patterns all express that something is not stated as a directly confirmed fact, but they use different evidence. 〜そう can show appearance or hearsay, 〜よう shows inference or resemblance, 〜みたい is a casual version for inference or resemblance, and 〜らしい shows information-based inference or typicality.
Formation
Appearance そう uses a stem form. Hearsay そう uses the plain form. よう uses plain form, noun + の, or な-adjective + な. みたい attaches directly to nouns and plain forms. らしい attaches to nouns or plain forms.
Usage
Use 〜そう for visible appearance or reported information, depending on the form. Use 〜ようだ for careful inference or resemblance. Use 〜みたいだ in casual speech. Use 〜らしい for information-based inference or when something is typical of a person, season, or thing.
Nuance
The most important question is the source of the judgment. Are you looking at it, hearing it from someone, inferring from evidence, speaking casually, or describing typical character? The answer helps choose the right pattern.
Comparison
この料理はおいしそうです is based on appearance. 彼はもう帰ったようです is an inference from the situation. 外は雨みたいです sounds casual. 明日は雪が降るらしいです is based on information.
Common Mistakes
A common mistake is translating all four as seems and ignoring the source. Japanese uses these patterns to show how the speaker knows or guesses something.
Related Grammar
〜そうだ（様態）
〜そうだ in the appearance sense means something looks or seems a certain way based on what you can see now.
〜そうだ（伝聞）
〜そうだ in the hearsay sense means I heard that or it is said that. It reports information from another source.
〜ようだ
〜ようだ expresses inference or resemblance. It is often used when something seems true based on evidence or when something is like something else.
〜みたいだ
〜みたいだ means seems like or looks like. It is a conversational pattern used for inference and resemblance.
〜らしい
〜らしい expresses inference from information or the idea that something is typical of someone or something.