Japanese Grammar Bank


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!


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

You can use 思う 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:


Adjective / Verb + と思う

明後日は雨だと思う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Shiken wa muzukashikatta to omoimasu.I think the exam was difficult.


Next, we’ll look at だろう as well as 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:

明日は雨が降るでしょう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.


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:

明日は晴れかもしれない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:

Ashita wa yuki ka mo.


It may snow tomorrow.
Karai ryouri wa tabenai ka mo.


I may not eat spicy meals.


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:

あれ?鍵をどこに置いたっけ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.

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What does と思う express in Japanese?

と思う 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.