Translation guide
Describes fruit, vegetables, or other things that are not yet fully developed or mature. In Japanese, the most common word is 未熟 (mijuku), but for fruit specifically, 青い (aoi) is often used. The choice depends on what is being described and the nuance.
To describe fruit or vegetables that are not yet ready to eat because they haven't fully ripened.
To describe something abstract or a person that is immature, inexperienced, or not yet fully formed.
The standard word for 'immature' or 'unripe' in a metaphorical sense. Applies to skills, ideas, people.
青い (aoi) is the everyday word for unripe fruit. 未熟 (mijuku) is more formal and can sound technical or literary. In casual speech, always prefer 青い for fruit.
While 青い means unripe for fruit, using it for a person (e.g., 彼は青い) would mean 'he is pale' or 'he is inexperienced' in a very slangy way. For 'immature person', use 未熟 or 青臭い.
These bananas are still unripe, so I can't eat them.
青いトマトは酸っぱい。
Unripe tomatoes are sour.
More formal/literary term for 'unripe' or 'immature'. Can be used for fruit, but also for skills or people. For fruit, 青い is more common in speech.
未熟な果実は市場に出せない。
Unripe fruit cannot be put on the market.
Literally 'not ripened'. A clear, neutral way to say unripe. Slightly more explanatory than 青い.
この柿はまだ熟していない。
This persimmon is still unripe.
彼の技術はまだ未熟だ。
His skills are still unripe (undeveloped).
未熟な計画では成功できない。
You can't succeed with an unripe (half-baked) plan.
Literally 'smells green', meaning inexperienced, naive, or immature. Often used for young people or their ideas. Slightly negative or critical.
彼の意見はまだ青臭い。
His opinions are still unripe (naive).
Means 'childish' or 'infantile'. Can be used for unripe ideas or behavior, but carries a stronger negative connotation of immaturity.
そんな幼稚な考え方は通用しない。
Such an unripe (childish) way of thinking won't work.