Translation guide
The English word "reliable" can describe people, things, or information that you can trust to work well, be consistent, or be accurate. Japanese expresses this concept through different words depending on what is being described and the nuance of trustworthiness.
Describing a person who is dependable, responsible, and can be counted on.
The most common and natural way to say a person is reliable. Literally 'becomes a reliance'. Used for friends, colleagues, family.
He is a really reliable person.
She's always reliable when I'm in trouble.
Emphasizes trustworthiness and integrity. Slightly more formal than 頼りになる. Often used in professional contexts.
He is a reliable business partner.
Refers to a steady, reliable, and sensible person. Often used for someone who is responsible and has their act together.
My younger sister is reliable and always helps me out.
Similar to 頼りになる but slightly more casual. Can imply you can count on someone's help or information.
What he says is not reliable.
Describing objects, devices, services, or methods that work consistently and without failure.
Literally 'high reliability'. The standard way to describe the reliability of products, systems, or data.
This car is reliable.
That data cannot be called reliable.
Can also be used for things, especially in casual speech. Implies you can rely on it to do its job.
This app is really reliable.
Means 'stable'. Often used for systems, internet connections, or performance that is consistent and reliable.
This server is reliable (stable).
Means 'certain' or 'sure'. Used for methods or means that are guaranteed to work.
Describing news, data, testimony, or sources that are accurate and trustworthy.
The most direct translation for trustworthy information. Used for sources, news, witnesses.
I heard it from a reliable source.
That news is reliable.
Means 'certain' or 'sure'. Often used for information that is confirmed and reliable.
We need reliable evidence.
Similar to 信頼できる but slightly more about believability and reputation. Often used for people's statements or media.
His story is reliable.
Describing something that always performs well, like a reliable employee, athlete, or product.
頼りになる is more about practical dependability (you can count on them to help), while 信頼できる is about trust and integrity (you believe they are honest and won't betray you). For machines, 信頼性が高い is the technical term, but 頼りになる is fine in casual speech.
Japanese often uses relative clauses or phrases like 頼りになる (literally 'becomes a reliance') instead of a single adjective. Saying 頼りな人 is not natural; use 頼りになる人.
確実な方法を教えてください。
Please tell me a reliable method.