Potential Form

Expressing the ability to do something

In Japanese, the ability to do a certain action is expressed by conjugating the verb rather than adding a word such as the words "can" or "able to" in the case of English. All verbs conjugated into the potential form become a ru-verb.

The Potential Form

Once again, the conjugation rules can be split into three major groups: ru-verbs, u-verbs, and exception verbs. However, the potential form of the verb 「する」 (meaning "to do") is a special exception because it becomes a completely different verb: 「できる」 （出来る）

It is also possible to just add 「れる」 instead of the full 「られる」 for ru-verbs. For example, 「食べる」 becomes 「食べれる」 instead of 「食べられる」. I suggest learning the official 「られる」 conjugation first because laziness can be a hard habit to break and the shorter version, though common, is considered to be slang.

Examples

（１）　漢字は書けますか？
- Can you write kanji?

（２）　残念だが、今週末は行けない。
- It's unfortunate, but can't go this weekend.

（３）　もう信じられない。
- I can't believe it already.

Potential forms do not have direct objects

The potential form indicates that something is possible but no actual action is actually taken. While the potential form remains a verb, since it is describing the state of something you must not use the direct object 「を」 as you have done with regular verbs. For example the following sentences are incorrect.

（誤）　富士山を登れた。
（誤）　重い荷物を持てます。

Here are the corrected versions:
（正）　富士山が登れた。- Was able to climb Fuji-san.
（正）　重い荷物が持てます。- Am able to hold heavy baggage.
Of course, the 「は」 or 「も」 particle is also possible depending on what you want to say.

Are 「見える」 and 「聞こえる」 exceptions?

There are two verbs 「見える」 and 「聞こえる」 that mean that something is visible and audible, respectively. When you want to say that you can see or hear something, you'll want to use these verbs. If however, you wanted to say that you were given the opportunity to see or hear something, you would use the regular potential form. However, in this case, it is more common to use the type of expression as seen in example （３）.

Examples

（１）　今日は晴れて、富士山が見える。
- It cleared up today and Fuji-san is visible.

（２）　友達のおかげで、映画はただで見られた。
- Thanks to [my] friend, [I] was able to watch the movie for free.

（３）　友達のおかげで、映画をただで見ることができた。
- Thanks to [my] friend, [I] was able to watch the movie for free.

You can see that （３） uses the generic noun for an event to say literally, "The event of seeing movie was able to be done." which essentially means the same thing as 「見られる」. You can also just use generic noun substitution to substitute for 「こと」.

（１）　友達のおかげで、映画を見るのができた。

Here's some more examples using 「聞く」, can you tell the difference? Notice that 「聞こえる」 always means "audible" and never "able to ask".

（１）　久しぶりに彼の声が聞けた。
- I was able to hear his voice for the first time in a long time.

（２）　周りがうるさくて、彼が言っていることがあんまり聞こえなかった
- The surroundings were noisy and I couldn't hear what he was saying very well。

「ある」, yet another exception

You can say that something has a possibility of existing by combining 「ある」 and the verb 「得る」 to produce 「あり得る」. This essentially means 「あることができる」 except that nobody actually says that, they just use 「あり得る」. This verb is very curious in that it can be read as either 「ありうる」 or 「ありえる」, however; all the other conjugations such as 「ありえない」、「ありえた」、and 「ありえなかった」 only have one possible reading using 「え」.

Examples

（１）　そんなことはありうる。
- That kind of situation/event is possible (lit: can exist).

（２）　そんなことはありえる。
- That kind of situation/event is possible (lit: can exist).

（３）　そんなことはありえない。
- That kind of situation/event is not possible (lit: cannot exist).

（４）　彼が寝坊したこともありうるね。
- It's also possible that he overslept. (lit: The event that he overslept also possibly exists.)

（５）　それは、ありえない話だよ。
- That's an impossible story/scenario. (lit: That story/scenario cannot exist.)