4 Ways to Express Probability in Japanese

Have you every wanted to express possibility and probability in Japanese, such as the likelihood of, for example, going to a party?

You’re in luck! Today, we’ll teach you a few ways to express probability and possibility in Japanese.

These ways can all be used to convey various degrees of uncertainty (‘maybe’, ‘probably,’ etc.) depending on context and tone of voice.

Yes, you have learned adverbs in Japanese previously that can help you state different levels of certainties, but these grammar patterns are easy too! You will master them in no time!

Let’s get started!

Probability in Japanese | と思う

Probability in Japanese | だろう・でしょう

Probability in Japanese | かもしれない

Probability in Japanese | っけ

Probability in Japanese | FAQ’s

Probability in Japanese | と思う・とおもう

This might be the verb that’s used the most in Japanese.

You can use 思う・おもう to express your certainty in everyday life, in almost all situations.

When you use 思う, your speech sounds like your personal opinion. If you need to speak objectively, the passive form is more suitable than the plain form.

Also, you can use 思う and 思います depending on the respect you want to give to the person you are talking with.

As you’ve learned when using Japanese plain forms, 思う can only be used when you’re talking with someone casually.

And you can change the tense of verbs by changing the form of adjective or verb before と思う.

Have a look at some examples:

ExampleHiraganaRomajiEnglish
明後日は雨だと思う。あさってはあめだとおもう。Asatte wa ame da to omou.I think it will be sunny the day after tomorrow.
試験は難しかったと思います。しけんはむずかしかったとおもいます。Shiken wa muzukashikatta to omoimasu.I think the exam was difficult.

Probability in Japanese | だろう・でしょう

Next, we’ll look at だろう・でしょう.

だろう can give a nuance of “probably” to sentences.

However, this sounds very masculine and thus we recommend you use the polite form, でしょう while talking in formal situations.

You can directly connect them with any element such as verbs, adjectives, and nouns. In practice, they are often used with adverbs in formal situations.

Here are some examples:

ExampleHiraganaRomajiEnglish
明日は雨が降るでしょう。あしたはあめがふるでしょう。Ashita wa ame ga furu deshou.It will probably be rainy tomorrow.
雪は降らないだろう。ゆきはふらないだろう。Yuki wa furanai darou.It probably won’t snow.

Note: だろう also has functions to confirm something and also for blaming someone. You will learn them in other lessons.

Probability in Japanese | かもしれない

かもしれない expresses there is some possibility for something to happen and can roughly be translated as “may” in English.

Just like だろう, you can connect かもしれない to any element without conjugation.

Take a look at some examples:

ExampleHiraganaRomajiEnglish
明日は晴れかもしれない。あしたははれかもしれない。Ashita wa hare kamoshirenai.It may be sunny tomorrow.
辛い料理は食べないかもしれません。からいりょうりはたべないかもしれません。Karai ryouri wa tabenai kamoshiremasen.I may not eat spicy meals.

In casual tone, people sometimes abbreviate かもしれない like the following. The meaning remains the same.

So again using above examples, we can say:

ExampleHiraganaRomajiEnglish
明日は雪かも。あしたはゆきかも。Ashita wa yuki ka mo.It may be sunny tomorrow.
辛い料理は食べないかも。からいりょうりはたべないかも。Karai ryouri wa tabenai ka mo.I may not eat spicy meals.

Probability in Japanese | っけ

The sentence-ending particle 「っけ」 is used to describe something you’re trying to recall such as a vague memory or something you recently forgot.

Have a look at some examples:

ExampleHiraganaRomajiEnglish
あれ?鍵をどこに置いたっけ?あれ?かぎをどおにおいたっけ?Are? Kagi wo doko ni oitakke?Huh? Where did I place the keys?
彼の名前は何でしたっけ?かれおなまえはなんでしたっけ?Kare no namae wa nan deshitakke?What was his name again?

Of course, you can use different adverbs that we have taught you with different degrees of certainties.

Using these grammar patterns will make you sound more native-like and will help you increase your fluency in Japanese.

Keep practicing these until we update with the next lessons!


That was an introduction on how to express probability Japanese.

You’ll certainly encounter these patterns many times during your Japanese journey, so take a look at this lesson any time you want to clarify their meaning or usage! 

Here are a few more important lessons to nail down:

If you ever fancy some Japanese classes, don’t forget about our Flexi Classes!

Japanese adverbs

FREQUENTLY ASKED QUESTIONS

What does と思う・とおもう express?

と思う・とおもう means “I think” when used after the plain form of a verb or adjective and is a way to express your personal opinion in casual, everyday situations.

What does でしょう mean?

でしょう is the polite form of だろう and also expresses “probably.”

It is a more neutral way to express “probably” and is used by both men and women.

What is the casual form of かもしれない?

The casual form of かもしれない is かも, and can also be used after plain form adjectives, adverbs, and verbs.

What does だろう mean?

だろう means “probably” and is added to the end of sentences.

It is a very masculine-coded sentence ender.

If you are a female, it is better to use the polite form or かな.

What does かもしれない express?

かもしれない means “might” or “may be” and is used after the plain form of verbs, adjectives, or adverbs.

Check out the rest of the article for examples!

What does っけ signify?

っけ signifies that one is trying to recall a memory or something they’ve forgotten, such as where their keys are.

It is added to the end of sentence, and can follow both the plain and polite forms of verbs.

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