Definition:
The potential form (可能形, kanō-kei) in Japanese expresses the ability or possibility to perform an action — corresponding to English constructions using “can,” “be able to,” or “it is possible to.” It is formed by modifying the verb stem according to the verb group and is commonly used in both spoken and written Japanese.
Forming the Potential Form
Group 2 verbs (Ichidan/ru-verbs): Replace -る with -られる
- 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)
- 起きる (okiru — to wake up) → 起きられる (okirareru — can wake up)
Group 1 verbs (Godan/u-verbs): Change the final -u to -e, then add -る
- 書く (kaku) → 書ける (kakeru — can write)
- 飲む (nomu) → 飲める (nomeru — can drink)
- 話す (hanasu) → 話せる (hanaseru — can speak)
- 買う (kau) → 買える (kaeru — can buy)
- 行く (iku) → 行ける (ikeru — can go)
Group 3 (irregular):
- する (suru) → できる (dekiru — can do, be able to do)
- 来る (kuru) → 来られる (korareru — can come)
Short-Form Potential (Colloquial Contraction)
In colloquial speech, the Group 2 potential -られる is commonly shortened to -れる (dropping the ら):
- 食べられる → 食べれる
- 見られる → 見れる
This contraction is called ra-nuki kotoba (ら抜き言葉 — “ra-deletion words”) and is very common in casual speech, though considered incorrect in formal writing by traditionalists. Most native speakers under 50 use it naturally.
Particle Usage with Potential Verbs
A key grammatical point: with potential forms, the direct object can be marked with either ? or ?:
- 日本語を話せる。(Nihongo wo hanaseru.) — I can speak Japanese. (を — slightly more focus on the act)
- 日本語が話せる。(Nihongo ga hanaseru.) — I can speak Japanese. (が — more common in natural speech)
Both are grammatically acceptable; ? is the more natural choice in most spoken contexts.
Common Uses
Expressing ability:
> 漢字が読めますか？— Can you read kanji?
> はい、少し読めます。— Yes, I can read a little.
Expressing possibility:
> 今日は来られない。— I can’t come today. (unable to)
> ここで泳げる。— You can swim here. (It’s possible here)
Expressing improved ability (progress):
> だんだん日本語が話せるようになった。— I’ve gradually become able to speak Japanese.
(~ようになる + potential = expressing a change in ability, very common in learner narratives)
Potential vs. Passive Confusion (Group 2)
For Group 2 verbs, the potential form (-られる) is identical to the passive voice (-られる):
- 食べられる — was eaten (passive) / could eat (potential)
Context disambiguates: passive uses ? subject + ? agent + ?/? object; potential uses ? or ? for the thing that can be done.
Common Misconceptions
“The potential form means the same thing as ことができる.”
While both express ability, the potential form (e.g., 読める, yomeru) is more natural and colloquial, while ことができる is more formal and literary. Using ことができる in casual speech sounds stiff, similar to saying “I am able to read” instead of “I can read” in English. The potential form is almost always preferred in conversation.
“Potential form always takes を for the direct object.”
When a verb is conjugated into potential form, the object particle typically shifts from を to が: 日本語が読める (can read Japanese), not 日本語を読める. While を is increasingly accepted in modern colloquial Japanese, the traditional grammar and standard usage is が. This particle shift is a frequent error for learners who assume potential works exactly like the base verb.
“見れる and 食べれる are grammatical errors.”
These shortened potential forms (ら抜き言葉, ra-nuki kotoba) — dropping the ら from 見られる and 食べられる — are widespread in modern spoken Japanese, particularly among younger speakers. While prescriptive grammar still considers them non-standard, they are common enough that ignoring them creates a gap between textbook Japanese and real-world usage. Learners should recognize both forms.
“Group 2 (ichidan) passive and potential forms are always ambiguous.”
While 食べられる can theoretically mean either “can eat” or “is eaten,” context almost always resolves the ambiguity. The spread of ra-nuki forms (食べれる for potential) is partly driven by speakers’ desire to disambiguate — learners can use 食べれる for potential to avoid confusion, especially in casual contexts.
Practical Application
For Japanese learners:
- The potential form is a high-priority intermediate grammar point — it appears constantly in real conversation (“can you read that?” “I can’t eat shellfish”)
- Learn ~ようになる alongside the potential form: this pattern (to become able to ~) is extremely useful for talking about your own language learning progressess
- Practice ra-nuki in speaking to sound natural; avoid it in formal written Japanese
- Pay attention to ? vs. ? with potential verbs — ? is more natural in speech for most verbs
- Sakubo
Related Terms
See Also
Research
- Makino, S., & Tsutsui, M. (1986). A Dictionary of Basic Japanese Grammar. The Japan Times. [Summary: Includes entries for both the potential form and the ら抜き言葉 structure with detailed contrastive examples — the standard reference for the grammar of ability expression in Japanese.]
- Hibiya, J. (1995). Perceiving Japanese: A first survey of the ra-nuki phenomenon. University of Pennsylvania Working Papers in Linguistics, 2(2). [Summary: Early sociolinguistic study of ra-deletion (ら抜き言葉) in Tokyo Japanese, establishing the generational and contextual patterns of the colloquial contraction and its spread through younger speaker populations.]