Translation guide
In Japanese, expressing likelihood involves a range of grammar patterns that convey probability, expectation, or tendency. The most common patterns are 〜そうだ (it looks like), 〜ようだ (it seems), 〜らしい (I hear / it seems), 〜かもしれない (might), and 〜はずだ (should be). The choice depends on the source of information (direct observation, hearsay, logical deduction) and the degree of certainty.
It looks like it's going to rain.
He might come.
He should be here soon.
Express that something appears likely based on what you see or feel right now.
Attach to the stem of verbs and adjectives to indicate that something seems likely based on direct observation. For い-adjectives, drop the final い; for な-adjectives, use the stem without な. The negative form is 〜そうにない／そうもない.
It looks like it's going to rain.
This cake looks delicious.
He looks well.
Express a conjecture or likelihood based on circumstantial evidence or reasoning.
Express that something is possible or might happen.
Expresses uncertainty or possibility. Can be shortened to 〜かも in casual speech. Follows plain form of verbs, adjectives, and nouns.
Express that something is expected or should be the case based on logical deduction.
Indicates a strong expectation that something is true based on reasoning. Follows plain form; for nouns and な-adjectives, use 〜のはずだ or 〜なはずだ.
Express that something has a tendency to happen or is likely to occur under certain conditions.
Indicates a tendency, often negative. Attaches to the stem of verbs or nouns. Commonly used for things that happen frequently or are prone to occur.
He tends to be late.
〜そうだ is for direct visual or intuitive judgment. 〜ようだ is for inference from evidence or situation. 〜らしい is for hearsay or typical characteristics. For example, seeing dark clouds → 雨が降りそうだ; feeling a drop of water → 雨が降ったようだ; hearing a forecast → 雨が降るらしい.
The sky is dark. It looks like rain.
In all likelihood, he will be late.
Using adverb おそらく (probably) with だろう for formal conjecture.
It seems someone has come.
He seems to be tired.
More casual and colloquial than 〜ようだ. Used in spoken Japanese. Follows nouns directly, and verbs/adjectives in plain form.
That person looks like a student.
It seems cold outside.
Indicates that something is likely based on hearsay or reasonable assumption. It can also express that something has the typical characteristics of something. Follows nouns, verbs, and adjectives in plain form.
He might come.
That might be true.
A more formal way to say 'there is a possibility of...'. Used in writing and formal speech. Follows nouns with の, or plain form of verbs/adjectives.
There is a possibility of delay.
He should have arrived by now.
That should be correct.
Expresses a strong conviction that something is certainly the case. More emphatic than 〜はずだ. Follows plain form.
He must be lying.
People tend to catch colds this time of year.
Means 'easy to do' or 'likely to happen'. Attaches to the stem of verbs. Can be used for both positive and negative tendencies.
This glass breaks easily.
地面が濡れている。雨が降ったようだ。
The ground is wet. It seems it rained.
According to the weather forecast, it's going to rain.
English often uses the noun 'likelihood', but Japanese prefers verbal or adjectival expressions. Instead of 'the likelihood of rain is high', say '雨が降りそうだ' or '雨の可能性が高い'. Direct translations like '可能性' can sound stiff in casual conversation.
The likelihood of rain is high. (formal)
There is little likelihood of success.
可能性 (possibility) is used here in a more formal or written context.