Can You Do It? Expressing Ability (～ことができます)

In Japanese, the structure ～ことができます (…koto ga dekimasu) is a versatile way to express the ability to do something. It translates to "can do," "to be able to do," or "is able to do." It's polite and widely applicable, making it a valuable tool for expressing your capabilities or asking about others' abilities.

Structure

The basic structure is as follows:

Verb (dictionary form) + ことができます

Let's break this down:

Verb (dictionary form): This is the plain, non-conjugated form of the verb, as you would find it in a dictionary. Examples include 食べる (taberu - to eat), 話す (hanasu - to speak), and 運転する (unten suru - to drive).
ことができます (koto ga dekimasu): This is a set phrase. こと (koto) is a noun meaning "thing" or "matter," and in this case, it turns the preceding verb into a noun-like phrase that can be the subject of the verb できます (dekimasu), which means "can do," "is possible," or "is able to do." が (ga) is the subject marker.

Examples

English	Japanese	Romaji	Explanation
I can swim.	泳ぐことができます。	oyogu koto ga dekimasu.	"oyogu" (to swim) + "koto ga dekimasu" (can do). The subject is implied.
She can write kanji.	彼女は漢字を書くことができます。	kanojo wa kanji o kaku koto ga dekimasu.	"kanojo wa" (as for her) + "kanji o" (kanji object marker) + "kaku" (to write) + "koto ga dekimasu" (can do).
We can come tomorrow.	私たちは明日来ることができます。	watashitachi wa ashita kuru koto ga dekimasu.	"watashitachi wa" (as for us) + "ashita" (tomorrow) + "kuru" (to come) + "koto ga dekimasu" (can do).
I can play the guitar.	私はギターを弾くことができます。	watashi wa gitā o hiku koto ga dekimasu.	"watashi wa" (as for me) + "gitā o" (guitar object marker) + "hiku" (to play - string instruments) + "koto ga dekimasu" (can do).
They can speak English.	彼らは英語を話すことができます。	karera wa eigo o hanasu koto ga dekimasu.	"karera wa" (as for them) + "eigo o" (English object marker) + "hanasu" (to speak) + "koto ga dekimasu" (can do).
He can cook Japanese food.	彼は日本料理を作ることができます。	kare wa nihon ryōri o tsukuru koto ga dekimasu.	"kare wa" (as for him) + "nihon ryōri o" (Japanese food object marker) + "tsukuru" (to make/cook) + "koto ga dekimasu" (can do).

More About できる (dekiru)

The verb できる (dekiru) itself means "to be able to do," "to be possible," or "to be ready." It's a very useful verb! できます (dekimasu) is the polite form. The ～ことができます structure utilizes this verb to express ability.

Nuance and Context

While ～ことができます is versatile, it's useful to understand its nuance:

Emphasis on Ability: It emphasizes the ability to perform an action, rather than the action itself.
Formality: It's considered more formal and polite than using potential forms (explained below). This makes it suitable for business situations, when speaking to superiors, or when you want to be extra polite.
Circumstances: It can imply that the ability exists but might not always be exercised due to circumstances. For example: "日本語を読むことができますが、あまり上手ではありません。(Nihongo o yomu koto ga dekimasu ga, amari jōzu dewa arimasen.)" - "I can read Japanese, but I'm not very good at it."

Subject Marking with は (wa)

As noted previously, the subject is often marked with は (wa) for emphasis or contrast. This highlights who possesses the ability.

例:

私はピアノを弾くことができます。 (Watashi wa piano o hiku koto ga dekimasu.) As for me, I can play the piano. (Implies that others might not be able to.)
妹は料理を作ることができます。 (Imōto wa ryōri o tsukuru koto ga dekimasu.) As for my younger sister, she can cook.

Alternative: Potential Forms (～られる/～れる)

As mentioned, Japanese also has "potential forms" for verbs, which directly express the ability to do something. These are often shorter and more casual than ～ことができます. However, not all verbs have easily formed potential forms, and the potential forms can sometimes sound less polite.

Here's how potential forms are created and some examples:

Group 1 Verbs (Godan): Change the final -u sound to -eru.
- 書く (kaku - to write) → 書ける (kakeru - can write)
- 泳ぐ (oyogu - to swim) → 泳げる (oyogeru - can swim)
- 話す (hanasu - to speak) → 話せる (hanaseru - can speak)
Group 2 Verbs (Ichidan): Drop the -ru and add -rareru.
- 食べる (taberu - to eat) → 食べられる (taberareru - can eat)
- 見る (miru - to see) → 見られる (mirareru - can see)
Irregular Verbs:
- する (suru - to do) → できる (dekiru - can do)
- 来る (kuru - to come) → 来られる (korareru - can come)

Examples comparing both forms:

English	Using ～ことができます	Romaji	Using Potential Form	Romaji
I can eat sushi.	寿司を食べることができます。	sushi o taberu koto ga dekimasu.	寿司が食べられる。	sushi ga taberareru.
I can read hiragana.	ひらがなを読むことができます。	hiragana o yomu koto ga dekimasu.	ひらがなが読める。	hiragana ga yomeru.
I can come tomorrow.	明日来ることができます。	ashita kuru koto ga dekimasu.	明日来られる。	ashita korareru.

Important Notes about Potential Forms:

Particle Change: Notice how the particle often changes from を (o) to が (ga) when using the potential form. This is because the potential form transforms the direct object into the subject of the sentence.
Politeness: While shorter, potential forms are generally less polite than ～ことができます. Use them with friends, family, or in informal situations.
Ambiguity: In some contexts, the potential form can also mean "is eaten," "is seen," etc. (passive voice). Context usually clarifies the meaning, but ～ことができます avoids this ambiguity.

Asking Questions with ～ことができますか (…koto ga dekimasu ka?)

To ask if someone can do something, simply add か (ka) to the end of the ～ことができます phrase.

Structure:

Verb (dictionary form) + ことができますか

Examples:

English	Japanese	Romaji
Can you speak Japanese?	日本語を話すことができますか。	Nihongo o hanasu koto ga dekimasu ka?
Can you drive a car?	車を運転することができますか。	Kuruma o unten suru koto ga dekimasu ka?
Can you use chopsticks?	箸を使うことができますか。	Hashi o tsukau koto ga dekimasu ka?
Can you see Mt. Fuji from here?	ここから富士山を見ることができますか。	Koko kara Fujisan o miru koto ga dekimasu ka?

Answering Questions:

Yes: はい、できます。(Hai, dekimasu.) - Yes, I can. / Yes, it's possible. (You can also use the full form: はい、～ことができます。 Hai, … koto ga dekimasu.)
No: いいえ、できません。(Iie, dekimasen.) - No, I can't. / No, it's not possible. (You can also use the full form: いいえ、～ことができません。Iie, … koto ga dekimasen.)

You can also give more detailed answers:

日本語を話すことができますか？ (Nihongo o hanasu koto ga dekimasu ka?)
- はい、少し話すことができます。(Hai, sukoshi hanasu koto ga dekimasu.) - Yes, I can speak a little.
- いいえ、全く話すことができません。(Iie, mattaku hanasu koto ga dekimasen.) - No, I can't speak it at all.

Beyond Abilities: Possibilities and Permissions

While primarily used for expressing abilities, ～ことができます can also express possibilities or permissions, although other grammar is usually preferred in those scenarios. The nuance shifts slightly.

Possibility (Less Common):

このホテルでは、クレジットカードを使うことができます。(Kono hoteru dewa, kurejitto kādo o tsukau koto ga dekimasu.) - At this hotel, you can use credit cards. (More naturally, one would say: このホテルでは、クレジットカードが使えます。Kono hoteru dewa, kurejitto kādo ga tsukaemasu.)

Permission (Less Common):

ここで写真を撮ることができます。(Koko de shashin o toru koto ga dekimasu.) - You can take pictures here. (More naturally, one would say: ここで写真を撮ってもいいです。Koko de shashin o totte mo ii desu.)

Common Mistakes

Forgetting the こと (koto): Saying just "泳ぐができます" (oyogu ga dekimasu) is grammatically incorrect. You need the こと (koto) to turn the verb into a noun phrase.
Incorrect Verb Form: Make sure you use the dictionary form of the verb before adding ことができます.
Mixing up Potential Form and ～ことができます: Remember that the potential form often changes the particle. Also, be mindful of the level of politeness.

Practice Exercises

Exercise 1: Translation

Translate the following sentences into Japanese using ～ことができます:

I can play the piano.
She can read Chinese.
We can see the fireworks tonight.
He can make delicious ramen.
They can sing Japanese songs.

Answers

私はピアノを弾くことができます。(Watashi wa piano o hiku koto ga dekimasu.)
彼女は中国語を読むことができます。(Kanojo wa Chūgokugo o yomu koto ga dekimasu.)
私たちは今夜花火を見ることができます。(Watashitachi wa kon'ya hanabi o miru koto ga dekimasu.)
彼は美味しいラーメンを作ることができます。(Kare wa oishii rāmen o tsukuru koto ga dekimasu.)
彼らは日本の歌を歌うことができます。(Karera wa Nihon no uta o utau koto ga dekimasu.)

Exercise 2: Question and Answer

Ask if someone can do the following, and then answer the question yourself.

Speak Korean
Use a computer
Cook Italian food
Ski
Play the drums

Example and Answers

Example:

Question: ギターを弾くことができますか。 (Gitā o hiku koto ga dekimasu ka?) - Can you play the guitar?
Answer (Yes): はい、ギターを弾くことができます。 (Hai, gitā o hiku koto ga dekimasu.) - Yes, I can play the guitar. OR はい、できます。(Hai, dekimasu.) - Yes, I can.
Answer (No): いいえ、ギターを弾くことができません。(Iie, gitā o hiku koto ga dekimasen.) - No, I cannot play the guitar. OR いいえ、できません。(Iie, dekimasen.) - No, I can't.

Answers:

- Question: 韓国語を話すことができますか。(Kankokugo o hanasu koto ga dekimasu ka?)
- (Your Answer Here)
- Question: コンピューターを使うことができますか。(Konpyūtā o tsukau koto ga dekimasu ka?)
- (Your Answer Here)
- Question: イタリア料理を作ることができますか。(Itaria ryōri o tsukuru koto ga dekimasu ka?)
- (Your Answer Here)
- Question: スキーをすることができますか。(Sukī o suru koto ga dekimasu ka?) Note: スキーをする (sukī o suru) is the common way to say "to ski."
- (Your Answer Here)
- Question: ドラムを演奏することができますか。(Doramu o ensō suru koto ga dekimasu ka?)
- (Your Answer Here)

Exercise 3: Potential Form Conversion

Convert the following sentences using ～ことができます to sentences using the potential form. (Where possible and natural).

私は日本語を読むことができます。(Watashi wa Nihongo o yomu koto ga dekimasu.)
彼女は上手に歌うことができます。(Kanojo wa jōzu ni utau koto ga dekimasu.)
彼は毎日早く起きることができます。(Kare wa mainichi hayaku okiru koto ga dekimasu.)
私たちは映画を見ることができます。(Watashitachi wa eiga o miru koto ga dekimasu.)
私は明日来ることができます。(Watashi wa ashita kuru koto ga dekimasu.)

Answers

私は日本語が読めます。(Watashi wa Nihongo ga yomemasu.)
彼女は上手に歌えます。(Kanojo wa jōzu ni utaemasu.)
彼は毎日早く起きられます。(Kare wa mainichi hayaku okiraremasu.)
私たちは映画が見られます。(Watashitachi wa eiga ga miraremasu.)
私は明日来られます。(Watashi wa ashita koraremasu.)