Translation guide
Describes a person, thing, or situation that cannot be relied on. In Japanese, this is expressed through adjectives, verbs, and descriptive phrases that emphasize unreliability, inconsistency, or lack of trustworthiness.
Describing a person who cannot be counted on to keep promises, show up, or do what they say.
The most common and neutral way to say someone is undependable. Literally 'does not become a reliance'.
彼は頼りにならない。
He is undependable.
That person doesn't keep promises, so they're undependable.
Similar to 頼りにならない but often used for things or information as well as people. Implies 'cannot be counted on'.
彼の言うことは当てにならない。
What he says is undependable.
Focuses on lack of trustworthiness. Stronger than 頼りにならない, implying the person might be dishonest.
あの男は信用できない。
That man is undependable (untrustworthy).
Describes someone who is irresponsible, sloppy, or half-hearted. Often used for people who don't take things seriously.
彼はいい加減な人だ。
He's an undependable (irresponsible) person.
Describing objects, data, weather, etc. that cannot be relied on to function or be accurate.
The go-to phrase for undependable things, forecasts, or information.
この天気予報は当てにならない。
This weather forecast is undependable.
インターネットの情報は当てにならないこともある。
Information on the internet can be undependable.
Means 'unstable' or 'unreliable' for systems, connections, or performance.
Formal/technical term for low reliability. Used in product reviews or technical contexts.
この機械は信頼性が低い。
This machine is undependable (has low reliability).
Describing something that varies in quality or performance, making it undependable.
Describes a person or thing that is whimsical, capricious, or unpredictable. Often used for people's moods or performance.
彼の仕事ぶりは気まぐれだ。
His work is undependable (erratic).
Literally 'has unevenness'. Used for inconsistent performance or quality.
あの選手はむらがある。
That player is undependable (inconsistent).
Means 'not stable', used for fluctuating things like internet connection or emotions.
ここのWi-Fiは安定しない。
The Wi-Fi here is undependable.
Both mean 'undependable', but 頼りにならない is more about relying on a person for support or help, while 当てにならない is about counting on something to happen or be true. 当てにならない is often used for information, forecasts, or promises.
彼は頼りにならないが、彼の情報は当てにならないわけではない。
He is undependable as a person, but his information is not necessarily undependable.
The English word 'undependable' doesn't have a single direct adjective in Japanese. Using 頼りにならない or 当てにならない is natural. Avoid trying to create a word like 不頼 (not a real word).
このアプリは不安定でよく落ちる。
This app is undependable and crashes often.