Basic Japanese Grammar: The Potential Form “I Can…”

Published March 8th, 2022

One of the best ways to improve your Japanese is by tackling one basic Japanese grammar at a time, and we do that in our Study Saturday language series of the Nihongo Master Podcast! In Season 3 Episode 4, we break down the grammar point of saying “I can” in Japanese, a useful grammar language that we can’t live without.

Whether it’s at work or just among friends, there will definitely come a time when you mention or respond with your abilities, capabilities or attributes. And sometimes, it doesn’t even have to be about you — it can be about the people around you or even things! Can the AC work? Can she make it in time? Can I sleep in today? All of these have different subjects, but they all still use the same grammar language.

If that’s not proof enough that this particular grammar point is extremely useful, then I don’t know what is.

So, this article will recap what we discussed in the podcast episode – introducing the grammar point and a few examples, as well as listing the new vocabulary words we used. If you want to know more in-depth about this grammar language, give Season 3 Episode 4 a listen!

Grammar Point

Expressing your capabilities and abilities are pretty useful in any language, and it’s not only useful to prove to your bosses of your skill set. In fact, this can definitely be used in everyday conversation.

This grammar point is known as the potential form, and there are two ways to express this.

Koto ga dekiru

The first one is by adding ~koto ga dekiru (ことができる) to the plain form of any verb. For the polite form, it’s “koto ga dekimasu” (ことができます). The format is:

Verb (plain form) + ことができる

For example, to say “I can eat spicy food”, we’ll need to put together the words for spicy, which is karai (辛い), food which can be either tabemono (食べ物) or ryōri (料理), and the verb “to eat” which is taberu (食べる). At the end of the sentence, all we have to do is add the phrase we mentioned earlier.

辛い + 料理 + は + 食べる + ことができる (polite: ことができます)

= 辛い料理は食べることができる (karai ryōri ha taberu koto ga dekiru.)

If you’re the opposite of me and cannot eat spicy food, just negate “dekiru” to make “dekinai” (できない). The polite form is then “dekimasen” (できません). This is to say “I cannot…”. The format is:

Verb (plain form) + ことがでない (polite: ことができません)

You get this sentence:

辛い料理は食べることができない (karai ryōri ha taberu koto ga dekinai)


The other way is slightly trickier — depending on whether it’s a -ru or u-verb, you would then have to conjugate it differently. We’ll use the same example about spicy food. For ru-verbs like “taberu”, you would need to take out the last syllable “ru”, and add “rareru” (られる) afterwards, to make “taberareru”. The polite form is “raremasu” (られます).

Ru-verb (take out the ending る) + られる (polite: られます)

食べる = 食べ (without る) + られる = 食べられる

So the sentence becomes: 辛いk料理は食べられる (karai ryōri ha taberareru)

If you want the negation, the ending “ru” becomes “nai”. For the formal, it’s “masen” instead.

Ru-verb (take out the ending る) + られない (polite: られません)

Casually, we can omit the “ra” in “rareru”, to make “reru” (れる) . Grammatically it’s incorrect, but it does sound more natural to most Japanese people today.

食べられる = 食べれる (more colloquial but grammatically incorrect)

For u-verbs, ;et’s use this sentence as an example: “I can speak a little bit of Japanese”.

The words in the sentence are:

A little bit: 少し (sukoshi)

Japanese: 日本語 (nihongo)

To speak: 話す (hanasu)

話す is an u-verb, so to conjugate it, we take the u sound at the end and change it to e, then add “ru” (る). For the polite form, the ru is substitute with “masu” (ます)

U-verb (without う) + え + る (polite: ます)

話す = はなす - う + え = 話せ = 話せる

The sentence in Japanese is:

日本語を少し話せる (nihongo wo sukoshi hanaseru)

The negation is the same as we mentioned before. The ending “ru” becomes “nai”. For the formal, it’s “masen” instead.

U-verb (without う) + え + ない (polite: られません)

話す = はなす - う + え = 話せ = 話せない

Irregular verbs

One quick thing to note: there are two irregular verbs that don’t conjugate like the rest, and that is suru (する) and kuru (来る).

Suru becomes dekiru (できる).

Kuru becomes korareru (来られる).

If you can’t remember, just use the safe option of koto ga dekiru — it’ll then be suru koto ga dekiru (することができる), and kuru koto ga dekiru (来ることができる). No change in meaning at all.

Vocab Recap

Here’s a list of vocabulary words that we used in the episode:

Karai 辛い— spicy

Tabemono 食べ物— food

Ryōri 料理— cuisine

Taberu 食べる— to eat

Sukoshi 少しor chotto ちょっと— a bit

Nihongo 日本語— Japanese. You can add -go語 to most countries to talk about their language. Spanish would then be supeingo スペイン語

Hanasu 話す— to speak

Jikoshoukai 自己紹介— self introduction

Gakureki 学歴— educational background

Kagaku 科学— science

Kyoumi 興味— interest

Kaisha 会社— company

Hataraku 働く— to work

Kouri 降臨— retail

Keiken 経験— experience

Dōryō 同僚— colleagues

Hayaku 早く— fast

Manabu 学ぶ) — to learn

Kenkyū 研究— research

Arubaito (アルバイト) — part-time job

Kōken (後見) — contribution

Kakushin (革新) — confident

Hiku (引く) — to play (an instrument)

Gakki (楽器) — instruments

Oto (音) —sound

Narau (習う) — to take lessons in, or to learn

Oyogu (泳ぐ) — to swim

We can do it!

This is a short but comprehensive guide on the potential form! For a more in-depth discussion as well as some examples in sentences, check out Season 3 Episode 4 of our Nihongo Master Podcast!