Something is useful when it helps you achieve a specific purpose or goal.
Word in 30 Seconds
- Used to describe something that helps achieve a goal.
- Can refer to physical tools or abstract information.
- Commonly used in both formal and informal contexts.
Usage Patterns
基本的には「〜に役立つ」という形で使われます。名詞に対して使う場合は「〜の役に立つ」という形も一般的です。また、過去形は「役立った」、否定形は「役立たない」となります。
Common Contexts
仕事のスキル、道具、アドバイス、情報、経験など、物理的なものから抽象的なものまで対象は広いです。例えば「この本は勉強に役立つ」「この道具は料理に役立つ」のように使います。
Similar Words comparison
「役に立つ」と「有用な」の違いについて。前者は動詞として動作や状態を説明するのに対し、「有用な」は形容動詞であり、より硬い表現として文章やビジネスの報告書などで好まれます。
Examples
この地図は旅行に役立つ。
everydayThis map is useful for traveling.
本プロジェクトの成功に役立つ情報を共有します。
formalI will share information that is useful for the project's success.
ネットの口コミは買い物に役立つね。
informalOnline reviews are helpful for shopping, aren't they?
この理論は将来の研究に役立つと考えられる。
academicThis theory is considered to be useful for future research.
Common Collocations
Common Phrases
役に立つもの
something useful
役に立たない
useless
役立てる
to make use of
Often Confused With
Refers to convenience or ease of use. Something can be 'benri' but not necessarily 'yakudatsu' for a specific goal.
Means effective or valid. Often used for rules, tickets, or specific methods.
Grammar Patterns
How to Use It
Usage Notes
The term is neutral and versatile. It can be used in both formal business settings and casual conversation. When using it in formal writing, '役に立つ' is often written as '役立つ' to maintain a concise tone.
Common Mistakes
Learners often use '役立つ' for people, which can sound rude. Also, ensure the particle 'ni' is used correctly to indicate the purpose. Avoid using it as an adjective directly modifying a noun (e.g., 'yakudatsu hon' is okay, but 'yakudatsu koto' is more common).
Tips
Use 'ni' particle for the target
Always connect the purpose with the particle 'ni'. For example, 'benkyou ni yakudatsu' means useful for study.
Avoid using for people directly
Calling a person 'yakudatsu' sounds objectifying. Use 'tasuke ni naru' or 'tayori ni naru' instead.
Modesty in Japanese culture
When someone says your help was useful, a humble response like 'iie, tondemonai desu' is often preferred.
Word Origin
Derived from 'yaku' (role/duty) and 'tatsu' (to stand). It literally means to stand in a position where one can fulfill a role.
Cultural Context
Japanese society values efficiency and practicality. Using the phrase 'yakudatsu' shows that you appreciate the utility of something, which is a positive trait in social interactions.
Memory Tip
Think of 'Yaku' (role) + 'Tatsu' (stand). A tool that 'stands up' to perform its 'role' is useful.
Frequently Asked Questions
4 questions意味はほとんど同じですが、「役に立つ」の方がより一般的で、口語的な響きがあります。「役立つ」は少し引き締まった響きがあり、文章やニュースなどでよく使われます。
「役立った」です。例えば「昨日のアドバイスはとても役立った」のように使います。
人に対して「彼は役立つ」と言うと、道具のように聞こえて失礼になることがあるので注意が必要です。人には「助けになる」や「頼りになる」を使う方が適切です。
「有益な」は「利益がある」というニュアンスが強く、ビジネスや学術的な文脈で使われます。「役立つ」はより広い状況で使える日常的な言葉です。
Test Yourself
この辞書は日本語の勉強に___。
文末として適切な丁寧語の形であるため。
新しいアプリは仕事の効率化に___。
効率化に役立つという自然なコロケーション。
（アドバイス / 役立った / くれた / 私の / に / は）
「私にくれた」が「アドバイス」を修飾する形が正しい。
Score: /3
Summary
Something is useful when it helps you achieve a specific purpose or goal.
- Used to describe something that helps achieve a goal.
- Can refer to physical tools or abstract information.
- Commonly used in both formal and informal contexts.
Use 'ni' particle for the target
Always connect the purpose with the particle 'ni'. For example, 'benkyou ni yakudatsu' means useful for study.
Avoid using for people directly
Calling a person 'yakudatsu' sounds objectifying. Use 'tasuke ni naru' or 'tayori ni naru' instead.
Modesty in Japanese culture
When someone says your help was useful, a humble response like 'iie, tondemonai desu' is often preferred.
Examples
4 of 4この地図は旅行に役立つ。
This map is useful for traveling.
本プロジェクトの成功に役立つ情報を共有します。
I will share information that is useful for the project's success.
ネットの口コミは買い物に役立つね。
Online reviews are helpful for shopping, aren't they?
この理論は将来の研究に役立つと考えられる。
This theory is considered to be useful for future research.
Related Content
This Word in Other Languages
Related Vocabulary
More academic words
絶対的
B2Absolute; not qualified or diminished in any way; total.
絶対的に
B1In a complete, unconditional, or conclusive manner; absolutely.
抽象的だ
B1Abstract; existing in thought or as an idea but not having a physical or concrete existence.
抽象
B2Existing in thought or as an idea but not having a physical or concrete existence. It refers to generalizing or extracting the essence of something away from specific details.
抽象的に
B1In an abstract or theoretical manner.
学術的な
B1Academic, scholarly; relating to education and scholarship.
学術的だ
B1Academic; relating to education and scholarship.
学術的
B2Academic; relating to education and scholarship.
学術
B1Academia; scholarship; relating to scholarly pursuits.
学力
B1Academic ability; a person's level of knowledge and skill in academic subjects.
