In order to express the potential in Japanese we need to conjugate the verb. The way we do so differs for Group 1, Group 2, and Group 3 verbs (just as it did when we conjugated the verbs into the negative, simple past, and negative past before).
For the potential form, all verbs will end with る and from then on out behave exactly the same as Group 2 verbs, meaning that changing from the present to the negative, simple past, and negative past is incredibly easy.
As we saw when we did some basic conjugations on verbs, remembering the layout of the hiragana table is helpful.
From the standard dictionary form we start with our “u” ending verb and this time skip one column to the right to change to an “e” ending character and then add る. The first few lines of the hirgana table again:
| あ | い | う | え | お |
| か | き | く | け | こ |
| さ | し | す | せ | そ |
| … | … | … | … | … |
Let’s take the verb to write (かく) as an example:
| かく | かけ | かける |
| Take the verb | Change the く to a け | Add る |
書ける means “can write” and can be treated like a Group 2 verb.
| Verb | Dictionary | Potential |
| to read | ||
| to wait | ||
| to reply | ||
| to go | ||
| to go home |
The Group 1 verb ある is an exception which we will look at below.
Very easy. We just replace る with られる.
| Verb | Dictionary | Potential |
| to see | ||
| to leave | ||
| to exist | いる | いられる |
Often in conversation the られる will be shortened to れる because this is less of a tongue-twister. So, for example, 見られる would become 見れる. However, this is not correct grammatical practice.
These two are awkward again. You just need to remember them. Be careful: “to come” looks like it conjugates the same as a Group 2 verb, but the phonetics for the kanji have changed from く to こ.
| Verb | Dictionary | Potential |
| to do | する | できる |
| to come |
From here we can treat ALL verbs as if they belong to Group 2. In other words, we can change the final る as per the following table to form the negative, past, and past negative.
| Potential | Neg. | Past | Past Neg. |
| Could not study. |
| Could not eat. |
| Cannot see. |
Now, technically when we use the potential form of the verb, the object particle を should be replaced with the particle が. So for the sentence, “I can put my bag here”:
ここにかばんを置けます。 (✘)
ここにかばんが置けます。(✔)
I say “technically” because modern day parlance makes allowances for either, although grammar conformists may shout otherwise. The reality is that you will hear both を and が used with the potential in both conversation and writing. The same rule bending does not, however, apply to the potential form of the verb “to do”. This needs the が particle. For example, “I can play tennis”:
テニスをできます。(✘)
テニスができます。(✔)
The が particle is again omitted if the verb takes a direct object. For example, “I can study Japanese”:
日本語を勉強ができます。(✘)
日本語を勉強できます。(✔)
There’s always a few verbs that have to be awkward.
1. ある。The potential form of this verb actually requires a less common structure (which you do not need to remember for either JLPT N4 or N5). This combines the stem of the verb with える. It is most often used with the negative as a phrase to express shock at a situation.
| ありえない。 |
| Cannot be (unbelievable). |
2. わかる。The verb “to understand” (
3. “to hear” and “to see”. These actually have two forms of the potential—each for different situations. This is another stumbling block for learners as we do not differentiate between these two meanings in English.
As we know from above, the standard potential form of “to hear” and “to see” is:
| Verb | Dictionary | Potential |
| to see (Gr. 2) | ||
| to hear (Gr. 1) |
In Japanese the potential form above implies that you have the ability to hear or see, not whether it’s naturally visible or audible to you in the first place. This is best understood through an example.
Say you’re sitting in an audience and there’s a tall guy seated in front of you blocking your view. In English we would just say, “I can’t see”, but we would in fact mean, “I do have the ability to see (= the power of sight), but I cannot see the stage because this guy’s head is in the way”. Japanese makes this distinction and in this situation you need use another form of the potential.
| Verb | Dictionary | Potential II |
| to see | ||
| to hear |
For example, “I can hear music from outside”:
Both 見える and 聞こえる must take が as their particle (you cannot use を).
For just about every verb we actually have at least two ways of forming the potential because we can nominalise the verb and then make it into a verb again by adding ができる. Sounds confusing, eh? Don’t worry, it’s all quite straight-forward!
| To eat. |
| The thing that is eating. |
| Can eat [can do the thing that is eating]. |
| I can read kanji. |
| I can swim. |
This form of expressing the potential doesn’t change the meaning, but is typically a little more formal (and therefore used more often in writing rather than conversation). It will likely come up on the JLPT N5 exam.