Formal Ability: Using 'Koto Ga Dekiru' (Can Do)
koto ga dekiru to express ability or possibility formally, turning the action into a noun phrase.
Grammar Rule in 30 Seconds
Use 'Koto ga dekiru' to express ability by nominalizing a verb with 'koto' and adding 'ga dekiru'.
- Attach 'koto' to the dictionary form of a verb: {泳ぐ|およぐ}こと.
- Add 'ga dekiru' to express ability: {泳ぐ|およぐ}ことが{出来|でき}る.
- Use 'ga' to mark the ability, not 'o': {日本語|にほんご}を{話|はな}すことが{出来|でき}る.
Overview
In Japanese, expressing ability is nuanced, often going beyond a simple "can." While the potential form (e.g., 書ける 'can write') is common for everyday speech, verb (dictionary form) + koto ga dekiru offers a distinct, more formal, and objectively oriented way to state capability. This construction literally translates to "the act of [verb] is possible," emphasizing the objective possibility or capability of an action rather than a personal, subjective ability or a circumstantial "can." It is the linguistic tool you reach for when you need to clearly and unambiguously state a skill, an allowable action, or a functionality. Unlike the potential form, which can sometimes imply a circumstantial ability or even willingness, koto ga dekiru consistently conveys a defined, inherent, or established capability.
Mastering this distinction is crucial for navigating formal Japanese communication, from job interviews to understanding official documents.
How This Grammar Works
koto ga dekiru operates by transforming an action into a noun, thereby allowing you to talk about the action itself as a concept or entity that possesses the quality of "being possible." This transformation process, known as nominalization, is fundamental to understanding this grammar point.- 1The Verb (Dictionary Form): You begin with any verb in its plain, non-conjugated dictionary form. This is the core action you wish to express capability for, such as 泳ぐ 'to swim' or 運転する 'to drive'. It is critical that the verb remains in this dictionary form, irrespective of the desired tense or politeness level of the overall statement.
- 2
koto(こと): This is the nominalizer. Its primary function here is to take the preceding verb (or verb phrase) and convert it into a noun phrase. For example, 泳ぐ 'to swim' becomes 泳ぐこと 'the act of swimming' or 'swimming'. This abstract noun phrase now represents the action as a discrete concept. - 3
ga({が}): This is the subject particle. Becausekotohas transformed the verb phrase into a noun, that noun phrase now acts as the grammatical subject of the sentence. The particlegamarks this subject. It signifies that "the act of [verb]" is what is possible. Withoutga, the grammatical relationship between the nominalized action anddekirubecomes ambiguous or incorrect. - 4
dekiru(できる): This is a verb meaning 'to be able to', 'to be possible', or 'can'. It is the predicate of the sentence, stating the possibility of the nominalized action.Dekiruitself is a る-verb, meaning its conjugation follows the standard pattern for る-verbs.
話すこと 'speaking' rather than simply stating 話せる 'can speak'.Formation Pattern
verb (dictionary form) + koto ga dekiru is straightforward, making it less prone to conjugation errors than some other complex structures. The simplicity lies in the fact that the main verb always retains its dictionary form, and only dekiru undergoes conjugation for tense, politeness, and negation.
Verb (Dictionary Form) + こと + が + できる
Conjugation Table
While the verb preceding koto always remains in its dictionary form, the verb dekiru itself conjugates like a regular {る |
ru}-verb. All tense, politeness, and negation are handled by dekiru. This means the complexity of the sentence's tense and politeness is encapsulated in the final verb dekiru, simplifying the structure of the preceding action. |
||||||
|---|---|---|---|---|---|---|---|
| Form | dekiru Conjugation |
Full Phrase Example ({行くこと | いくこと} 'the act of going') | English Equivalent | |||
| :-------------- | :------------------- | :---------------------------------------------------- | :------------------------------------- | ||||
| Plain Present | {できる | できる} | {行くことができる | いくことができる} | Can go / Is able to go | ||
| Plain Past | {できた | できた} | {行くことができた | いくことができた} | Could go / Was able to go | ||
| Plain Negative | {できない | できない} | {行くことができない | いくことができない} | Cannot go / Is unable to go | ||
| Plain Past Negative | {できなかった | できなかった} | {行くことができなかった | いくことができなかった} | Could not go / Was unable to go | ||
| Polite Present | {できます | できます} | {行くことができます | いくことができます} | Can go (polite) / Is able to go (polite) | ||
| Polite Past | {できました | できました} | {行くことができました | いくことができました} | Could go (polite) / Was able to go (polite) | ||
| Polite Negative | {できません | できません} | {行くことができません | いくことができません} | Cannot go (polite) / Is unable to go (polite) | ||
| Polite Past Negative | {できませんでした | できませんでした} | {行くことができませんでした | いくことができませんでした} | Could not go (polite) / Was unable to go (polite) | ||
You can also use volitional, conditional, or other grammatical forms with dekiru to express more complex nuances. For instance, to say "If you can go..." you would use {行くことができれば |
いくことができれば}. This flexibility makes koto ga dekiru a highly adaptable structure for various communicative needs. Always ensure the nominalized verb remains in dictionary form, regardless of dekiru's conjugation. |
||||||
| - {彼はもう漢字を読むことができました | かれはもうかんじをよむことができました}. (He was already able to read kanji.) | ||||||
| - {このアプリは、オフラインでも使用することができません | このアプリは、オフラインでもしようすることができません}. (This app cannot be used even offline.) | ||||||
| - {来週までにレポートを提出することができますか | らいしゅうまでにレポートをていしゅつすることができますか}? (Can you submit the report by next week?) |
When To Use It
koto ga dekiru technically expresses "can" or "able to," its usage is more restricted and formal than the simple potential form. You choose this structure when you want to convey a sense of objectivity, formality, or emphasis on the inherent possibility of an action.- 1Stating Objective Facts and Capabilities:
koto ga dekiru is the preferred choice. It removes ambiguity and states a capability as a concrete, verifiable fact. This is common when discussing personal skills, product features, or established rules.- 私は英語と日本語を話すことができます. (I can speak English and Japanese. Common in self-introductions or resumes, stating a core skill.)
- このソフトウェアは、複数のファイルを同時に処理することができます. (This software can process multiple files simultaneously. Describes a feature or functionality of a product.)
- このエリアでは、喫煙することができます. (You can smoke in this area. States an allowed condition or rule in a public space.)
- 1Formal or Professional Contexts:
koto ga dekiru lends a more polite, professional, and serious tone compared to the more casual potential form. This is especially true in written communication, presentations, or job interviews where precise, unambiguous language is valued.- この度、貴社にご協力することができます. (We are able to cooperate with your company on this occasion. Used in formal business correspondence to convey a willingness and capability.)
- 研究結果について発表することができます. (I can present the research findings. Suitable for formal academic or professional presentations.)
- 1Written Rules, Guidelines, and Official Announcements:
koto ga dekiru is almost universally employed. It explicitly states what is permissible, possible, or a function, leaving no room for misinterpretation.- お客様は、購入後30日以内であれば商品を返品することができます. (Customers can return products within 30 days of purchase. Found in policy documents or online terms of service.)
- 入館者は、写真撮影をすることができますが、フラッシュの使用はできません. (Visitors can take photos, but cannot use flash. Posted rules in a museum or art gallery.)
- 1Emphasizing the Act or Condition of Possibility:
koto ga dekiru is more appropriate. It elevates the action to a conceptual level, often used for philosophical statements or complex scenarios. This is particularly useful when the action is an entire clause or a multi-word concept.- 人間は空を飛ぶことができますか? (Can humans fly in the sky? Focus on the objective possibility of 'flying' as an action for humans.)
- 過去を変えることはできません. (You cannot change the past. An abstract statement about the impossibility of altering history.)
- 1With Complex Verb Phrases:
koto ga dekiru is often preferred because koto neatly packages the entire phrase into a single noun unit. This improves sentence structure and clarity, especially when the verb phrase includes adverbs or multiple components.- この難しい問題を一人で解決することができますか? (Can you solve this difficult problem alone? Nominalizes the entire complex phrase 'to solve this difficult problem alone'.)
Common Mistakes
koto ga dekiru. Understanding these pitfalls and their underlying reasons is key to accurate usage.- 1Conjugating the Verb Before
koto:
koto. Remember, koto requires the pure, dictionary form of the verb.- Incorrect: ❌ 書けますことができます. (Incorrectly using the potential form {書ける} before
koto.) - Incorrect: ❌ 書きますことができます. (Incorrectly using the polite ます-form.)
- Correct: ✅ 書くことができます. (Always dictionary form.)
- Reason:
Kotoacts as a nominalizer for the plain, dictionary form of the verb. Any prior conjugation would alter the verb's basic meaning or grammatical state, thus disrupting the nominalization process. Think of it as "the act of [unconjugated action]" – the action itself, not its conjugated state, is being made into a noun.
- 1Omitting
ga:
ga might occasionally be dropped. However, relying on this habit leads to grammatically incomplete and potentially ambiguous sentences in formal or even semi-formal contexts. It sounds abrupt and unpolished.- Informal/Ambiguous: ⚠️ 泳ぐことできる.
- Correct: ✅ 泳ぐことができる.
- Reason: The nominalized phrase
verb + kotofunctions as the grammatical subject of the verbdekiru. Subjects in Japanese are primarily marked by the particlega. Omitting it blurs the subject-predicate relationship, making the sentence grammatically unsound in standard Japanese.
- 1Using
woinstead ofga:
dekiru itself often takes ga when expressing ability with a direct object (e.g., 漢字が読める), learners might mistakenly apply this to koto ga dekiru if they conceptualize koto as a direct object being acted upon. This is a common misapplication of particle rules.- Incorrect: ❌ 運転することをできます.
- Correct: ✅ 運転することができます.
- Reason: The phrase
verb + kotois the subject ofdekiru, not its direct object. The sentence states that "the act of driving is possible," not "I can do the act of driving." The focus is on the possibility of the action, which functions as the subject.
- 1Overuse in Casual Conversation:
koto ga dekiru in situations where the potential form is much more natural can make your speech sound overly stiff, formal, or even pedantic. While grammatically correct, it can create an unnatural tone and distance in informal settings.- Awkwardly Formal: 今日、早く帰ることができます? (Can you go home early today? - Sounds too formal for a simple, everyday question among colleagues or friends.)
- More Natural: 今日、早く帰れますか?
- Reason: The potential form (
~れる/~られる) is the default, neutral, and most common way to express "can" in most everyday situations.Koto ga dekirucarries a specific nuance of formality and objectivity that isn't always appropriate for casual interactions, where brevity and directness are often preferred.
- 1Confusing "Circumstantial Possibility" with "Inherent Capability":
koto ga dekiru implies objective capability, the potential form can often imply that something "can" happen due to circumstances or that one "feels able" to do something. The nuances are subtle but significant.koto ga dekiru: このピザを全部食べることはできます. (I am physically capable of eating this whole pizza. Emphasizes the objective physical capacity.)- Potential form: このピザを全部食べられます. (I can eat this whole pizza - perhaps because I'm very hungry, or there are no other restrictions that would prevent me. Focuses on circumstantial or internal willingness/feeling.)
- Reason: The potential form is more flexible, encompassing both objective ability and circumstantial possibility.
Koto ga dekiru, by nominalizing the action, makes a more direct and often more formal statement about the absolute possibility of that action.
Contrast With Similar Patterns
koto ga dekiru is straightforward in its construction, its usage contrasts sharply with other related patterns.- 1Vs. Potential Form (～れる/られる):
koto ga dekiru (e.g., 読むことができる) |が for object (e.g., 本が読める). | Nominalization (こと) + が + できる. |- Example 1 (Personal ability):
- Potential: 私は漢字が読めます. (I can read kanji. - Normal, everyday statement.)
koto ga dekiru: 私は漢字を読むことができます. (I can read kanji. - More formal, perhaps in a job interview or self-introduction where clarity and formality are desired.)
- Example 2 (Situational possibility):
- Potential: 今日は早く帰れます. (I can go home early today. - Due to circumstances.)
koto ga dekiru: 今日は早く帰ることはできますが、仕事が多いです. (I am able to go home early today, but I have a lot of work. - Emphasizes the objective possibility, often followed by a condition or caveat.)
- 1Vs.
~you ni naru(～ようになる): Becoming Able to Do Something:
koto ga dekiru: 私は日本語を話すことができます. (I can speak Japanese. - States current ability.)~you ni naru: 日本語を話せるようになりました. (I became able to speak Japanese. - Implies a progression, wasn't able before but now is.)
~you ni naru explaining how the ability (koto ga dekiru) was achieved.- 1Vs.
~koto ga kanou da(～ことが可能だ): Being Possible/Feasible:
Kanou da (可能だ) is an adjectival noun meaning 'possible' or 'feasible'. When combined with koto ga, it often conveys a very similar meaning to koto ga dekiru but can sound even more detached and technical, especially in written language. Dekiru feels slightly more active, whereas kanou da is more purely descriptive of possibility.- この計画を実行することができます. (We can execute this plan.)
- この計画を実行することが可能です. (It is possible/feasible to execute this plan.)
kanou da sometimes being preferred in highly technical or strictly objective reports.Real Conversations
Understanding koto ga dekiru goes beyond grammar rules; it involves recognizing its role in various communicative settings. While primarily formal, its presence in specific contexts highlights its utility for clarity and precision.
1. Professional/Business Context:
- Scenario: A project manager explaining capabilities in a meeting.
- Japanese: このシステムは、リアルタイムでデータを分析することができます。また、複数のユーザーが同時にアクセスすることも可能です. (This system can analyze data in real-time. Also, multiple users can access it simultaneously.)
- Observation: The use of することができます and することも可能です emphasizes the system's objective features and capabilities, suitable for a professional discussion.
2. Official Announcements/Instructions:
- Scenario: A sign at a facility or an online FAQ.
- Japanese: 当施設内では、飲食することができますが、特定のエリアでは禁止されています。詳細は掲示をご確認ください. (You can eat and drink within this facility, but it is prohibited in certain areas. Please check the notices for details.)
- Observation: することができます is used to clearly state a general rule or permission, while 禁止されています ([きんしされています]) indicates a restriction. This objective language is standard for official communications.
3. Job Interviews/Self-Introduction (Formal):
- Scenario: Responding to a question about skills.
- Japanese: 私は、新しい環境にもすぐに適応することができます。チームワークを重視し、円滑なコミュニケーションを取ることができます. (I can quickly adapt to new environments. I value teamwork and can communicate smoothly.)
- Observation: This construction allows for a polished, confident, and professional presentation of one's abilities, contrasting with the more casual feel of the potential form.
4. Explaining Complex Abilities:
- Scenario: A scientist explaining a new discovery's implications.
- Japanese: この技術を使えば、従来不可能だったことを実現することができます. (If we use this technology, we can achieve things that were conventionally impossible.)
- Observation: 従来不可能だったこと (things that were conventionally impossible) is a complex phrase that koto ga dekiru elegantly nominalizes, allowing the sentence to clearly state the possibility of achieving it.
Progressive Practice
Mastering koto ga dekiru requires deliberate practice that builds on your understanding of its nuances and formal applications. Move beyond simple sentence construction to differentiate its usage from the potential form.
Direct Translation & Transformation:
- Start with simple English sentences: Translate sentences like "I can read Japanese" or "You can use a credit card" into both the potential form and koto ga dekiru. Analyze the subtle differences in nuance and context. For instance, "I can swim" can be 泳げる (general ability) or 泳ぐことができます (formal statement of capability).
- Transform sentences: Take sentences using the potential form and try to rephrase them using koto ga dekiru. Identify situations where the transformation feels natural and where it creates an awkward, overly formal tone.
Contextual Dialogue Creation:
- Formal Role-play: Imagine scenarios like a job interview, a business presentation, or explaining product features. Write short dialogues or monologues where koto ga dekiru would be the most appropriate choice to express capability or permission. Pay attention to the overall politeness level.
- Official Document Snippets: Practice writing short, rule-based statements or disclaimers, such as those you'd find in a museum, a user manual, or an online service's terms and conditions. Focus on using koto ga dekiru to state clear, objective possibilities or prohibitions.
Active Listening & Reading:
- Identify Usage: As you consume Japanese media (news articles, official websites, formal speeches, business emails), actively listen for instances of koto ga dekiru. Note the context in which it's used and consider why the speaker/writer chose it over the potential form. Compare this to its use in casual dramas or anime.
- Shadowing: Practice repeating sentences that use koto ga dekiru from native speakers. Mimic their intonation and pacing to internalize the natural flow of these formal expressions.
Error Correction Drills:
- Self-Correction: After writing sentences using koto ga dekiru, revisit them and check for common mistakes: is the verb in dictionary form? Is ga present? Is the usage appropriate for the context?
- Peer Review: If possible, exchange sentences with a language partner or instructor for feedback, specifically focusing on the appropriate application of koto ga dekiru versus other ability expressions.
Quick FAQ
no ({の}) instead of koto ({こと})?Yes, ~no ga dekiru ({~のができる}) exists and is grammatically correct, as no can also function as a nominalizer. However, no ga dekiru is significantly more casual and spoken. It often feels more emphatic or focuses on the manner of doing something rather than the general possibility. For a safe, universally applicable, and formal choice, especially in written or professional contexts, always default to koto ga dekiru. No is usually reserved for more informal conversations or when pointing out something specific.
koto ga dekiru only for human abilities?No. It can be used for the capabilities of machines, systems, and even abstract possibilities. It's about the objective possibility of an action or event, regardless of the agent. For example, このカメラは暗い場所でも撮影することができます (This camera can take pictures even in dark places) describes a camera's feature, not a human's ability. Similarly, 明日、雨が降ることはできますか? (Is it possible for it to rain tomorrow?) talks about a natural possibility.
You conjugate dekiru into its past tense form. The verb preceding koto remains in dictionary form. So, for "I could run" or "I was able to run," you would say 走ることができました (polite) or 走ることができた (plain). Remember, the main verb 走る 'to run' never changes.
You negate dekiru. So, "cannot" becomes dekinai (できない) in plain form or dekimasen (できません) in polite form. For example, 運転することができません (I cannot drive/It is not possible to drive). The past negative would be dekinakatta (できなかった) or dekimasen deshita (できませんでした).
koto ga dekiru?Yes, you can. Adjectives modify the verb before it is nominalized. 速く走ることができます (I can run fast). Here, 速く ([はやく]) is an adverb modifying 走る 'to run'. If you want to say something like "It is possible to be happy," you'd use the verb form of the adjective: 幸せになることができます (You can become happy), not 幸せなこと.
koto ga dekiru always imply a positive ability?While most examples focus on positive abilities, it can also be used in negative contexts to state an impossibility, as seen in 過去を変えることはできません (You cannot change the past). It functions to state an objective truth about what is or is not possible.
Formation Table
| Form | Verb Type | Structure | Example |
|---|---|---|---|
|
Affirmative
|
All
|
Dict + こと + が + {出来|でき}る
|
{泳ぐ|およぐ}ことが{出来|でき}る
|
|
Negative
|
All
|
Dict + こと + が + {出来|でき}ない
|
{泳ぐ|およぐ}ことが{出来|でき}ない
|
|
Past
|
All
|
Dict + こと + が + {出来|でき}た
|
{泳ぐ|およぐ}ことが{出来|でき}た
|
|
Polite
|
All
|
Dict + こと + が + {出来|でき}ます
|
{泳ぐ|およぐ}ことが{出来|でき}ます
|
|
Polite Neg
|
All
|
Dict + こと + が + {出来|でき}ません
|
{泳ぐ|およぐ}ことが{出来|でき}ません
|
|
Question
|
All
|
Dict + こと + が + {出来|でき}ますか
|
{泳ぐ|およぐ}ことが{出来|でき}ますか
|
Meanings
This structure is used to express that someone has the ability or the possibility to perform an action.
Acquired Skill
Expressing a learned ability.
“{泳ぐ|およぐ}ことが{出来|でき}ます。”
“{自転車|じてんしゃ}に{乗|の}ることが{出来|でき}ます。”
Reference Table
| Form | Structure | Example |
|---|---|---|
|
Affirmative
|
Verb(dict) + こと + が + {出来|でき}る
|
{話|はな}すことが{出来|でき}る
|
|
Negative
|
Verb(dict) + こと + が + {出来|でき}ない
|
{話|はな}すことが{出来|でき}ない
|
|
Polite
|
Verb(dict) + こと + が + {出来|でき}ます
|
{話|はな}すことが{出来|でき}ます
|
|
Past
|
Verb(dict) + こと + が + {出来|でき}た
|
{話|はな}すことが{出来|でき}た
|
|
Question
|
Verb(dict) + こと + が + {出来|でき}ますか
|
{話|はな}すことが{出来|でき}ますか
|
Formality Spectrum
{日本語|にほんご}を{話|はな}すことが{出来|でき}ます。 (Self-introduction)
{日本語|にほんご}を{話|はな}すことが{出来|でき}る。 (Self-introduction)
{日本語|にほんご}を{話|はな}せるよ。 (Self-introduction)
日本語いけるよ。 (Self-introduction)
The 'Koto ga Dekiru' Concept
Usage
- Formal Business
- Objective Rules
Components
- こと Nominalizer
- が Particle
- {出来|でき}る Possible
Examples by Level
{日本語|にほんご}を{話|はな}すことが{出来|でき}ます。
I can speak Japanese.
{泳ぐ|およぐ}ことが{出来|でき}ます。
I can swim.
{料理|りょうり}を{作|つく}ることが{出来|でき}ます。
I can cook.
{歌|うた}うことが{出来|でき}ます。
I can sing.
{明日|あした}、{来|く}ることが{出来|でき}ますか？
Can you come tomorrow?
{ここ|ここ}で{写真|しゃしん}を{撮|と}ることは{出来|でき}ません。
You cannot take photos here.
{宿題|しゅくだい}を{終|お}わらせることが{出来|でき}ました。
I was able to finish the homework.
{彼|かれ}は{走|はし}ることが{出来|でき}ません。
He cannot run.
{専門的|せんもんてき}な{知識|ちしき}を{提供|ていきょう}することが{出来|でき}ます。
I can provide specialized knowledge.
{会議|かいぎ}に{参加|さんか}することが{出来|でき}ない{場合|ばあい}は、{連絡|れんらく}してください。
If you cannot attend the meeting, please contact me.
{複雑|ふくざつ}な{問題|もんだい}を{解決|かいけつ}することが{出来|でき}る{人|ひと}を{探|さが}しています。
We are looking for someone who can solve complex problems.
{計画|けいかく}を{変更|へんこう}することが{出来|でき}るか{確認|かくにん}します。
I will check if it is possible to change the plan.
{環境|かんきょう}への{影響|えいきょう}を{最小限|さいしょうげん}に{抑|おさ}えることが{出来|でき}る{技術|ぎじゅつ}です。
It is a technology that can minimize the impact on the environment.
{彼|かれ}の{意見|いけん}を{受|う}け{入|い}れることが{出来|でき}る{状況|じょうきょう}ではありません。
It is not a situation where I can accept his opinion.
{予算|よさん}を{増|ふ}やすことが{出来|でき}るか{検討|けんとう}しています。
We are considering whether it is possible to increase the budget.
{長期的|ちょうきてき}な{視点|してん}で{考|かんが}えることが{出来|でき}る{人材|じんざい}が{必要|ひつよう}です。
We need personnel who can think from a long-term perspective.
{前例|ぜんれい}のない{事態|じたい}に{対応|たいおう}することが{出来|でき}る{柔軟性|じゅうなんせい}が{求|もと}められます。
Flexibility that can respond to unprecedented situations is required.
{多角的|たかくてき}な{分析|ぶんせき}を{行|おこな}うことが{出来|でき}る{研究|けんきゅう}チームです。
It is a research team that can conduct multifaceted analysis.
{市場|しじょう}の{動向|どうこう}を{予測|よそく}することが{出来|でき}る{ツール|つーる}を{導入|どうにゅう}しました。
We introduced a tool that can predict market trends.
{文化|ぶんか}の{壁|かべ}を{越|こ}えることが{出来|でき}る{対話|たいわ}が{重要|じゅうよう}です。
Dialogue that can transcend cultural barriers is important.
{歴史|れきし}の{教訓|きょうくん}を{現代|げんだい}に{活|い}かすことが{出来|でき}る{知性|ちせい}が{問|と}われています。
An intellect that can apply the lessons of history to the present is being questioned.
{抽象的|ちゅうしょうてき}な{概念|がいねん}を{具体化|ぐたいか}することが{出来|でき}る{能力|のうりょく}は{稀有|けう}です。
The ability to concretize abstract concepts is rare.
{複雑|ふくざつ}な{社会|しゃかい}システムを{再構築|さいこうちく}することが{出来|でき}る{政策|せいさく}が{必要|ひつよう}です。
Policies that can reconstruct complex social systems are necessary.
{自己|じこ}の{限界|げんかい}を{超|こ}えることが{出来|でき}る{精神力|せいしんりょく}が{彼|かれ}にはあります。
He possesses the mental strength that can transcend his own limits.
Easily Confused
Both express ability, but potential verbs are more casual.
Both 'koto' and 'no' nominalize verbs.
Dekiru can also mean 'to be completed'.
Common Mistakes
{食べた|たべた}ことが{出来|でき}る
{食べる|たべる}ことが{出来|でき}る
{泳ぐ|およぐ}ことを{出来|でき}る
{泳ぐ|およぐ}ことが{出来|でき}る
{泳ぐ|およぐ}が{出来|でき}る
{泳ぐ|およぐ}ことが{出来|でき}る
{泳ぐ|およぐ}ことを{出来|でき}ます
{泳ぐ|およぐ}ことが{出来|でき}ます
{泳ぐ|およぐ}ことが{出来|でき}ましたか？
{泳ぐ|およぐ}ことが{出来|でき}ますか？
{泳ぐ|およぐ}ことが{出来|でき}ないです
{泳ぐ|およぐ}ことが{出来|でき}ません
{泳ぐ|およぐ}ことの{出来|でき}る
{泳ぐ|およぐ}ことが{出来|でき}る
{泳げる|およげる}ことが{出来|でき}る
{泳ぐ|およぐ}ことが{出来|でき}る
{泳ぐ|およぐ}ことが{出来|でき}る{人|ひと}は{少|すく}ないです
{泳ぐ|およぐ}ことが{出来|でき}る{人|ひと}は{少|すく}ないです (Correct, but check context)
{泳ぐ|およぐ}ことが{出来|でき}る{つもり|つもり}です
{泳ぐ|およぐ}ことが{出来|でき}ます
{泳ぐ|およぐ}ことが{出来|でき}る{こと|こと}は{知|し}っています
{泳ぐ|およぐ}ことが{出来|でき}る{こと|こと}は{知|し}っています (Correct, but check style)
{泳ぐ|およぐ}ことが{出来|でき}る{よう|よう}に{な|な}りました
{泳ぐ|およぐ}ことが{出来|でき}る{よう|よう}に{な|な}りました (Correct, but check meaning)
Sentence Patterns
___ことが{出来|でき}ます。
___ことが{出来|でき}ません。
___ことが{出来|でき}るか{確認|かくにん}します。
___ことが{出来|でき}る{人|ひと}を{探|さが}しています。
Real World Usage
{英語|えいご}を{話|はな}すことが{出来|でき}ます。
{写真|しゃしん}を{編集|へんしゅう}することが{出来|でき}るよ！
{ここ|ここ}で{切符|きっぷ}を{買|か}うことが{出来|でき}ますか？
{配達|はいたつ}を{追跡|ついせき}することが{出来|でき}ます。
{パスワード|ぱすわーど}を{変更|へんこう}することが{出来|でき}ません。
{図書館|としょかん}で{本|ほん}を{借|か}りることが{出来|でき}ます。
Use 'ga' not 'o'
Dictionary Form Only
Formal vs Casual
Politeness
Smart Tips
Use 'koto ga dekiru' instead of potential verbs.
Remember: Dekiru = Ga.
Use this structure to list your skills.
Use 'koto ga dekimasen' for prohibitions.
Pronunciation
Dekiru
The 'r' sound is a flap, like the 'tt' in 'better'.
Rising
Dekimasu ka↑
Questioning ability.
Memorize It
Mnemonic
Think of 'Koto' as a 'Container' that holds the verb, and 'Dekiru' as the 'Key' that opens the door to possibility.
Visual Association
Imagine a heavy dictionary (the verb) being put into a box (koto). Once in the box, you can lift it easily (dekiru).
Rhyme
Verb in the dictionary, add 'koto' to make it stationary, then 'ga dekiru' makes it visionary.
Story
Ken wanted to climb a mountain. He couldn't just say 'climb'. He had to put 'climb' into a box called 'koto'. Then he added 'ga dekiru' to show he had the ability. Now he is at the top!
Word Web
Challenge
Write 5 sentences about things you can do at work or school using this structure.
Cultural Notes
Using 'koto ga dekimasu' is preferred in emails to show professionalism.
Rules often use this structure to state what is allowed.
Younger people often drop 'koto ga' and just use the potential verb.
Derived from the verb 'dekiru' (to come into existence) and the nominalizer 'koto'.
Conversation Starters
{何|なに}をすることが{出来|でき}ますか？
{明日|あした}、{手伝|てつだ}うことが{出来|でき}ますか？
{会社|かいしゃ}で{何|なに}をすることが{出来|でき}ますか？
{将来|しょうらい}、{何|なに}を{達成|たっせい}することが{出来|でき}ると{思|おも}いますか？
Journal Prompts
Common Mistakes
Test Yourself
{泳ぐ|およぐ}こと___ {出来|でき}ます。
Which is correct?
Find and fix the mistake:
{食べる|たべる}ことを{出来|でき}ます。
{話|はな}すことが{出来|でき}ます。
こと / {出来|でき}る / {泳ぐ|およぐ} / が
Match each item on the left with its pair on the right:
{行|い}くことが{出来|でき}る
Dekiru is transitive.
Score: /8
Practice Exercises
8 exercises{泳ぐ|およぐ}こと___ {出来|でき}ます。
Which is correct?
Find and fix the mistake:
{食べる|たべる}ことを{出来|でき}ます。
{話|はな}すことが{出来|でき}ます。
こと / {出来|でき}る / {泳ぐ|およぐ} / が
Match the sentence.
{行|い}くことが{出来|でき}る
Dekiru is transitive.
Score: /8
Practice Bank
12 exercises{日本|にほん}の{歌|うた}を ___ ことができます。(I can sing Japanese songs.)
I cannot drive a car.
{漢字|かんじ}を{読みます|よみます}ことができます。
Match the phrases.
English: I can speak a little Japanese.
I can play (do) tennis.
{納豆|なっとう}を{食|た}べること ___ できますか？
I was able to meet him yesterday.
{昨日|きのう}、{走|はし}ることができます。
English: You cannot enter here.
この{漢字|かんじ}を ___ ことができますか？ (Can you read this Kanji?)
Context: Explaining store rules to a customer.
Score: /12
FAQ (8)
It is more formal and allows for clearer emphasis on the action.
Yes, e.g., '{勉強|べんきょう}することが{出来|でき}ます'.
Yes, it nominalizes the verb.
You can, but potential verbs are more common.
Yes, '{出来|でき}ます', '{出来|でき}ました', '{出来|でき}ません'.
It is grammatically incorrect.
Very often, it is standard for polite ability statements.
Yes, it can imply permission or possibility.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
Poder + infinitive
Spanish conjugates the helper verb; Japanese does not.
Pouvoir + infinitive
Japanese requires a nominalizer.
Können + infinitive
German word order is different.
Potential conjugation
Potential verb is one word; 'koto ga dekiru' is a phrase.
Yastati' an + verb
Arabic uses a specific particle 'an'.
Nenggou + verb
Chinese does not nominalize.
Learning Path
Prerequisites
Learn These First
Potential Form: Can you do it? (U-verbs)
Overview Japanese verbs undergo significant transformations to convey different meanings, and the potential form is a cr...
Japanese Potential Form: Saying 'I Can' for ru-verbs (～られる)
Overview The **potential form** in Japanese expresses ability or possibility: "can do," "is able to do," or "it is possi...
Related Videos
Related Grammar Rules
Japanese Potential Form: Saying 'I Can' for ru-verbs (～られる)
Overview The **potential form** in Japanese expresses ability or possibility: "can do," "is able to do," or "it is possi...
Leaving Things Messy or Unfinished (~っぱなし)
Overview At the B2 level, your focus shifts from merely constructing correct sentences to conveying precise nuance, emo...
Becoming able to do something (～ようになる)
Overview Japanese grammar often provides tools to express not just actions, but the context and trajectory surrounding...
Japanese Passive Form: U-Verbs (Ukemi-kei)
Overview The Japanese passive form, known as `Ukemi-kei` (`受身形`), allows you to describe an action as being performed...
Unacceptable Behavior: Using 〜まじき (Should Not)
Overview The Japanese grammar pattern `〜まじき` delivers a powerful, formal condemnation of an action or attitude, deem...
