Also appears inHearsay & Conjecture

Expresses the speaker's conjecture about something they are not fully certain about. でしょう is the polite form; だろう is the plain form used in casual conversation and written language. The degree of confidence is moderate — weaker than 〜に違いない (N3) but stronger than 〜かもしれない (N4). When the main clause expresses the speaker's personal thought, adding と思います is more natural than using でしょう alone. Do not confuse with the confirmation usage (確認) where the speaker expects agreement.

Also appears inHearsay & Conjecture

Used with rising intonation to seek confirmation or agreement from the listener. The speaker expects or assumes the listener knows or agrees. でしょう (polite) is the most common form; だろう is directed at friends or used in monologue. Equivalent to '..., right?' in English. In casual speech, でしょ／だろ are often used. When directed at a superior, でしょう is acceptable but じゃないですか is sometimes preferred as softer.

Used to report information heard from someone else without adding your own judgment. The source is often implicit, contrasting with 〜と言われている which explicitly attributes the statement. Never used with visual evidence — for that, use the non-hearsay 〜そうです (N3). Does not inflect: always 〜そうです regardless of tense. Do not confuse with the N3 〜そうだ that means 'it looks like' (样态), which attaches to stems (V-ますstem / イAdj-く / NaAdj-で / N-で).

Used to quote a commonly held opinion, a saying, or a reported statement. と言われている is the passive form ('it is said that ~') and does not specify who is saying it — it conveys a widely held view or transmitted knowledge. と言います is the respectful form when quoting what someone specifically said. For hearsay not explicitly quoted, 〜そうです is more concise. The quoted content before と should be in plain form.

Combines 〜だろう (conjecture) with と思います (I think) to express a tentative personal opinion. This softens the statement considerably compared to unmitigated 〜だろう, making it sound more humble and less assertive. Often preceded by たぶん. A common and natural way for learners to express conjectures politely. In casual speech, 〜だろうと思う is the plain equivalent; in writing, 〜であろうと思われる is an even more formal variant.

Used when the speaker has some evidence or information that leads them to believe something, combining reasoning with hearsay. Unlike 〜そうだ (pure hearsay), 〜らしい implies the speaker has done some thinking based on available clues or multiple sources. The information may come from rumors, news, or deductive reasoning from observed facts. It conveys less certainty than 〜ようだ (which stresses direct observation) but more than just guessing. 〜らしい can also attach directly to nouns to mean '~-like, typical of ~' (e.g., 男らしい 'manly').

Expresses a possibility that the speaker considers uncertain, roughly equivalent to 'might' or 'maybe' in English. かもしfれません is the polite form; かもしれない is the plain form. The degree of probability is lower than 〜でしょう (N5) and much lower than 〜に違いない (N3). Often used with adverbs like もしかすると / もしかして ('perhaps'). When かもしれない follows a negative statement, it can express faint hope (e.g., まだ間に合うかもしれない 'we might still make it').

Expresses the speaker's logical expectation based on known facts, prior information, or common sense. It conveys strong confidence grounded in reasoning — not blind belief. The key nuance is 'given what I know, this should be the case.' Contrast this with 〜に違いない (N3), which is also strong but based more on conviction than on factual premises. The negative form is 〜はずがない ('it can't be that ~'), expressing strong doubt or denial based on reasoning. Remember the special attachment for nouns (N-の + はず) and na-adjectives (NaAdj-な + はず).

Also appears inStandard & Basis·Standard & Basis

Expresses a judgment based on the speaker's direct observation or sensory input — what they see, hear, feel, or read. This is the key difference from 〜らしい (N4), which draws on hearsay or indirect evidence. 〜ようだ implies the speaker has firsthand sensory data. Also used metaphorically (e.g., まるで夢のようだ 'it's like a dream'). Attachment: nouns take の (N-のようだ), na-adjectives take な (NaAdj-なようだ). The polite form is 〜ようです. Similar to 〜みたいだ (N4, more colloquial counterpart).

A formal way to convey information obtained from someone else, often used in business or official contexts. とのことだ is an even more formal variant, common in workplace reports and news summaries, derived from 〜とのこと(です) dropping the copula in the embedded clause. Both are more formal than 〜そうです (N4). 〜ということだ also has a second, non-hearsay meaning: 'that is to say, it means that ~' (explaining or rephrasing). Context determines which reading applies.

Casual hearsay marker, commonly used in informal conversation where the speaker is not sure of the information's accuracy or cannot vouch for it. Often combined with 聞く (〜とか聞いた 'I heard something about ~'). The information is vague — it signals a lower commitment to the truth of the statement compared to 〜そうです. Do not confuse with the listing 〜とか ('things like ~, for example ~') where とか connects nouns. In the hearsay use, とか comes at the end of the quoted clause.

Expresses the speaker's strong conviction or belief that something is true, based on reasoning or intuition. Like 'must be' in English, it is a subjective opinion — not necessarily backed by objective proof. Similar to 〜はずだ (N4) but the ground for 〜に違いない is more subjective and conviction-based; 〜はずだ requires a logical premise. Also similar to 〜にきまっている (N3), but 〜にきまっている is even stronger and almost dismissive of alternative possibilities. In writing, often used with に違いないだろう for a softer assertion.

Used in formal contexts — news reports, official warnings, and written announcements — to indicate there is a risk or fear of an undesirable event occurring. The word おそれ (恐れ) literally means 'fear/dread,' so the outcome is always negative or undesirable. Never used for neutral or positive possibilities. Commonly appears in weather warnings (警報), disaster notices, and medical warnings. Nouns attach with の. Similar to but more formal than 〜かもしれない (N4); narrower in scope because the outcome must be harmful.

Expresses an inference the speaker draws from visible signs or outward appearances. The speaker observes something and reaches a conclusion — 'seeing X, I conclude Y.' Often used when the speaker notices a change in someone's appearance, behavior, or a situation. 〜とみえて is the te-form or continuative form that connects to an outcome; 〜とみえる is the sentence-ending form. Similar to 〜ようだ (N4) but with added emphasis on the inferential process from visible evidence.

Also appears inAssertion & Definitive Assessment·Judgment & Evaluation·Obligation, Permission & Advice

Classical negative conjecture form equivalent to 〜ないだろう. Primarily used in written Japanese and formal speech; has a literary, sometimes archaic flavor. Can express negative volition ('I will not ~') as well as negative conjecture ('probably won't ~'). The group 2 and irregular verb dual conjugation patterns (e.g., 食べるまい vs 食べまい) reflect competing classical rules, with the dictionary-form version (食べるまい) being more common in modern usage. Not used in everyday conversation; learners will encounter it mostly in novels, essays, and formal written arguments.

Expresses that a negative or undesirable outcome is quite possible, even likely. The verb かねる literally means 'to find difficult to do,' so かねない (the negative of かねる) means 'not find it difficult to do' — i.e., 'could easily do.' Always used with negative-outcome verbs (e.g., 事故になりかねない 'could easily lead to an accident'). Similar to 〜おそれがある (N2) but more colloquial and often used in everyday warnings. The opposite, 〜かねる, means 'cannot bring oneself to do' or 'find it hard to.'

A formal, written-language equivalent of 〜に違いない (N3), expressing strong conviction. 相違 means 'difference/discrepancy,' so 相違ない literally means 'there is no discrepancy' — i.e., 'it is indubitably the case.' Used in formal documents, legal writing, and somewhat old-fashioned official prose. Stronger than 〜に違いない in tone due to its literary register. In spoken language, it sounds overly formal or theatrical. The structure is identical to 〜に違いない (noun + に + 相違ない).

A formal rhetorical question formula that presents a conjecture while softening it into a suggestion rather than a direct assertion. ではあるまいか is the modern equivalent of the classical 〜ではあるまいか, combining では + ある + まい + か. The double-negative structure (まい + か) makes it more tentative than 〜だろう — the speaker is floating an idea for consideration. Commonly used in academic writing, editorials, and formal commentary. When the preceding element is a verb or adjective, のではあるまいか is sometimes used for nominalization.