Ability and potential can be expressed in two different ways.

(1) Attaching the phrase "~ koto ga dekiru （～??????）" after the basic form of the verb. "Koto (??)" literally means "thing," and "dekiru (???)" means "can" or "be able to~". The formal form of "~ koto ga dekiru （～??????）" is "~ koto ga dekimasu （～???????）". The past tense is "~ koto ga dekita” and “~ koto ga dekimashita" is used in formal situations.

• Nihongo o hanasu koto ga dekiru. ????????????｡ --- I can speak Japanese.
• Yumi wa kuruma no unten o suru koto ga dekimasu ka. ?????????????????｡ --- Can Yumi drive a car?
• Piano o hiku koto ga dekimasu. ?????????????｡ --- I can play piano.
• Yuube yoku neru koto ga dekita. ????????????｡ --- I slept well last night.
• Kono chiketto o tsukau koto ga dekimasen deshita. ????????????????????｡ --- I could not use this ticket.

"~ dekiru (～???)" can be directly attached to a noun, if a verb is closely associated with its direct object.

• Tomu wa Nihongo (o hanasu koto) ga dekiru. ??????(?????)????? --- Tom can speak Japanese.
• Naomi wa Piano (o hiku koto) ga dekimasu. ??????（?????）?????｡ --- Naomi can play piano.
• Watashi no chichi wa ryouri (o suru koto) ga dekimasen. ??????（?????）???????--- My father can't cook.

(2) Another way to express ability and possibility is to use the potential form of the verb. Potential verb forms are created as shown below.

Here is how to make the potential form from the basic form.

U-verbs: Replace the final "~u" with "~eru".

• iku (to go) ?? - ikeru ???
• kaku (to write) ?? - kakeru ???
• hanasu (to speak) ?? - hanasesru ???
• kau (to buy) ?? - kaeru ???
• asobu (to play) ?? – asoberu ???

RU-verbs: Replace the final "~ ru" with "~ rareru".

• miru (to see) ?? – mirareru ????
• taberu (to eat) ??? – taberareru ?????
• deru (to leave) ?? - derareru ????
• neru (to sleep) ?? – nerareru ????

Irregular verbs

• kuru (to come) ?? – koreru ???
• suru (to do) ?? – dekiru ???

In informal conversation, "~ra (～?)" is often dropped from the potential form of RU-verbs. For example, "mireru (???)" and "tabereru (????)" instead of "mirareru (????)" and "taberareru (?????)." Although both forms are commonly used, the standard form is "mirareru" or "taberareru".

There are no potential verbs for "aru (to exist, to have)," "kureru (to give)" and "wakaru (to understand)."

The potential form of the verb can be replaced with "~ koto ga dekiru (～??????)" without changing the meaning. It is more colloquial and less formal to use the potential form of the verb.

• Supeingo o hanasu koto ga dekiru. ??????????????｡ --- I can speak Spanish.
• Supeingo o hanaseru. ?????????｡ --- I can speak Spanish.
• Sashimi o taberu koto ga dekiru. ????????????? --- I can eat raw fish.
• Sashimi o taberareru. ????????｡ --- I can eat raw fish.
• Hikouki de Tokyo made ichi-jikan de iku koto ga dekiru. ????????????????????｡ --- I can go to Tokyo in an hour by plane.
• Hikouki de Tokyo made ichi-jikan de ikeru. ???????????????｡ --- I can go to Tokyo in an hour by plane.
• Doko de sono kutsu o kau koto ga dekimasu ka. ?????????????????｡ --- Where can I buy those shoes?
• Doko de sono kutsu ga kaemasu ka. ????????????｡ --- Where can I buy those shoes?

Exercises

Here are some exercises. Translate into Japanese.

(1) I can write hiragana.
(2) I can't drive a car.
(3) Can you play guitar?
(4) Tom could read this book when he was five.
(5) Can I buy the ticket here?

Here are the answers to the exercises.

(1) Hiragana o kaku koto ga dekiru/dekimasu. ?????????????/????｡
Hiragana ga kakeru/kakemasu. ????????/????｡

(2) Unten suru koto ga dekinai/dekimasen. ???????????/??????
Unten ga dekinai/dekimasn. ???????/?????｡

(3) Gitaa o hiku koto ga dekimasu ka. ??????????????｡
Gitaa ga hikemasu ka. ?????????｡
Gitaa hikeru. ??????？ (With rising intonation, very informal)

(4) Tomu wa gosai no toki kono hon o yomu koto ga dekita/dekimashita. ????????????????????/??????
Tomu wa gosai de kono hon o yometa/yomemashita. ?????????????/??????

(5) Kokode kippu o kau koto ga dekimasu ka. ????????????????｡
Kokode kippu o kaemasu ka. ???????????｡
Kokode kippu kaeru. ????????？ (With rising intonation, very informal)