に足る / に足りる means can do; worthy; worth doing. It is a JLPT N1 Japanese grammar pattern used to express that something has enough value or reason to be done — that it is worthy of a particular action or trust.
This grammar point often appears in formal speech, written opinions, and JLPT N1 reading passages. If you want to say that a person, thing, or action merits being done or trusted, に足る is a concise, precise choice that adds weight to your Japanese.
に足る isn't about physical ability — it's about whether the situation merits the action. You use it to draw a line between what's worth doing and what isn't.
What does に足る mean?
Use に足る when you want to state that something has enough value, reason, or quality to be done, believed, or experienced.
Natural translations include:
- worth doing; worthy of; enough to; can be done
に足りる is the modern equivalent and carries the same meaning, but に足る is more common in formal writing. The negative form に足らない (or に足りない) means not worth doing.
Focus on whether the speaker is evaluating worth, not ability.
How to form に足る
dictionary form + に 足る → …するに足る
You can replace 足る with 足りる in spoken or less stiff contexts; both are accepted, but 足る is preferred in formal writing and on the JLPT.
The negative form attaches 足らない (from 足りる) or 足りない to に:
- 読むに足らない → not worth reading
- 信頼に足りない → not trustworthy
The pattern is always に + 足る / 足りる, never ことを足りる or に足っている. Treat it as a fixed compound.
When is に足る used?
Use に足る in situations like:
- evaluating whether a person deserves trust, praise, or attention
- judging whether a book, film, or event is worth your time
- stating that an explanation, argument, or reason is sufficient
- making strong, formal value statements
Tone and register:
- formal to very formal; common in editorials, reports, and essays
- shows clear, often critical, judgment
- rare in casual chat — in everyday conversation you would more likely say ～に値する or a simpler phrase
に足る example sentences
After reading each sentence, ask what job に足る is doing: evaluating whether the action or quality is sufficient / worthy.
Nuance of に足る
The key nuance is a subjective judgment of worth or sufficiency. It’s not about capability — it’s about the speaker’s personal (or collective) standard for what “deserves” to be done.
This matters because learners often equate に足る with “can do”, missing the evaluative stance. A phrase like 話すに足る相手 means “someone worthwhile to talk to”, not just “a person you can talk to.”
Points to note:
- に足る almost always comes from the speaker’s perspective, implying the speaker is setting the bar.
- Negative forms (に足らない / に足りない) are very common and often carry a dismissive tone.
- Using に足る instead of a simple ～できる upgrades the sentence from a factual statement to a value judgment.
- The phrase tends to appear in critical reviews, formal critiques, and strong opinions.
に足る vs に値する
Both に足る and に値する can be translated as “worthy of”, but they are used in different contexts.
Quick contrast:
- 読むに足る本：a book with enough substance to be worth reading.
- 賞賛に値する努力：effort that deserves praise, because effort and praise match.
If both translations seem possible, check whether the sentence is about enough (足る) or deserving reciprocity (値する). The tone will guide you.
Common mistakes with に足る
A reliable self-check: write your sentence with に足る, then replace it with ほど価値がある. If the tone feels forced or overly dramatic, you probably wanted a simpler form.
Is に足る on the JLPT?
- sentence-equivalence questions (choose the same meaning)
- usage questions that test the negative form に足らない
- reading passages with strong opinion or critique
Practice questions for に足る
Once the structure feels natural, add context that makes the judgment clear.
Learning path for に足る
Related grammar to review next
- に — the foundational particle; seeing how it combines with 足る deepens your feel for evaluation patterns.
- に値する — the direct “worthy of” partner; essential for contrast.
- にあって — another N1 に-pattern that expresses a situation or role, often used in formal evaluations.
- に引き換え — shows contrast, useful after you’ve made a judgment with に足る.
Learn に足る with Hane
If you want to review に足る together with the related patterns above, Hane helps you practice Japanese in short, focused sessions. Each grammar point comes with example sentences, quick checks, and level-appropriate drills.
Browse more lessons here:
FAQ about に足る
What does に足る (ni taru / ni tariru) mean in Japanese?
に足る (ni taru / ni tariru) means “can do; worthy; worth doing”. It is JLPT N1 grammar. Use に足る when you want to state that something has enough value, reason, or quality to be done, believed, or experienced.
How do you form に足る (ni taru / ni tariru)?
Verb dictionary form + に 足る → …するに足る Noun + に 足る → 信頼に足る You can replace 足る with 足りる in spoken or less stiff contexts; both are accepted, but 足る is preferred in formal writing and on the JLPT.
What is the difference between に足る and に値する?
に足る: judgment of sufficiency. に値する: judgment of equivalent value.
What is an example sentence with に足る (ni taru / ni tariru)?
彼は信頼するに足る人物です。 — He is a person worthy of trust.