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Lesson 16: Opinions & Possibilities (と思う・かも・だろう)

Share opinions and possibilities: 〜と思います, 〜かもしれない, 〜だろう, and 〜んです for reasons and gentle explanations.

Expressing Opinions with 〜と思います

In Japanese, 〜と思おもいます is used to express personal opinions or thoughts in a polite manner. This construction attaches to the plain form of verbs, adjectives, or nouns, softening your statement by implying that it is simply your opinion.

Formation

Plain form of verb/adjective/noun + と思います

Expressing Opinions with と思います

Verb

行いく → 行いくと思おもいます
I go → I think I will go

い-Adjective

面白おもしろい → 面白おもしろいと思おもいます
Interesting → I think it is interesting

な-Adjective

簡単かんたんだ → 簡単かんたんだと思おもいます
Simple → I think it is simple

Noun

先生せんせいだ → 先生せんせいだと思おもいます
Is a teacher → I think he/she is a teacher

Examples in Context

この映画えいがは 面白いおもしろい と思います。

Kono eiga wa omoshiroi to omoimasu.

I think this movie is interesting.


明日あしたは 晴れるはれる と思います。

Ashita wa hareru to omoimasu.

I think it will be sunny tomorrow.


彼かれは 来るくる と思います。

Kare wa kuru to omoimasu.

I think he will come.

Negative Opinions

To express a negative opinion, use the negative plain form before と思います:

それは正ただしくないと思います。

Sore wa tadashikunai to omoimasu.

I don't think that is correct.

Note: Negative opinion about correctness


彼かれは来こないと思います。

Kare wa konai to omoimasu.

I think he won't come.

Note: Negative expectation about someone's action

Casual Form: 〜と思う

In casual speech, many people use
〜と思おもう
instead of
〜と思おもいます:

この料理りょうりは美味おいしいと思う。

Kono ryōri wa oishii to omou.

I think this food is delicious.

Note: Casual opinion expression


今日きょうは寒さむいと思わない?

Kyō wa samui to omowanai?

Don't you think it's cold today?

Note: Casual question seeking agreement

Cultural Insight:
Japanese conversations frequently employ
〜と思おもいます
as a softer way to present opinions. This indirect approach acknowledges subjectivity and helps maintain harmony. It's considered more polite than making direct assertions, as it shows you recognize that others may have different views.

Expressing Possibility with ~かもしれない

The structure ~かもしれない is used to indicate uncertainty or possibility—much like "might," "maybe," or "could be" in English. It expresses a medium level of certainty - it's not definite, but there's a reasonable chance.

Formation

Plain form of verb/adjective/noun + かもしれない (casual) / かもしれません (polite)

Verb

雨あめが降ふる → 雨あめが降ふるかもしれない
It rains → It might rain

い-Adjective

難むずかしい → 難むずかしいかもしれない
Difficult → It might be difficult

な-Adjective

元気げんきだ → 元気げんきだかもしれない
Healthy → They might be healthy

Noun

先生せんせいだ → 先生せんせいだかもしれない
Is a teacher → They might be a teacher

Examples in Context

雨あめが 降るふる かもしれない。

Ame ga furu kamoshirenai.

It might rain.


彼かれは 忙しいいそがしい かもしれません。

Kare wa isogashii kamoshiremasen.

He might be busy.


テストは 難しいむずかしい かもしれない。

Tesuto wa muzukashii kamoshirenai.

The test might be difficult.

Negative Possibility

To express that something might not happen, use the negative plain form:

彼女かのじょは来こないかもしれません。

Kanojo wa konai kamoshiremasen.

She might not come.

Note: Polite negative possibility


間まに合あわないかもしれない。

Ma ni awanai kamoshirenai.

I might not make it in time.

Note: Casual negative possibility

Adding Extra Nuance with Adverbs

You can combine かもしれない with adverbs to add nuance:

多分たぶん雨あめが降ふるかもしれない。

Tabun ame ga furu kamoshirenai.

It will probably rain. / It might rain.

Note: Using たぶん for added probability


もしかしたら彼かれは来こないかもしれない。

Moshikashitara kare wa konai kamoshirenai.

He might not come, maybe.

Usage Tip:
かもしれない is often preceded by expressions like
多分たぶん
(probably)
or
もしかしたら
(perhaps) to further highlight uncertainty.

Cultural Note:
Japanese speakers often prefer expressions of uncertainty like かもしれない rather than making definitive statements, especially when discussing future events or situations where they don't have complete information. This reflects a cultural preference for humility and avoiding overconfidence.

Expressing Probability with ~だろう/~でしょう

~だろう (casual) and ~でしょう (polite) express probability or likelihood with more certainty than かもしれない, similar to "probably" or "I suppose" in English.

Formation

Plain form of verb/adjective/noun + だろう (casual) / でしょう (polite)

Verb

行いく → 行いくだろう / 行いくでしょう
Go → Will probably go

い-Adjective

寒さむい → 寒さむいだろう / 寒さむいでしょう
Cold → Will probably be cold

な-Adjective

元気げんきだ → 元気げんきだろう / 元気げんきでしょう
Healthy → Will probably be healthy

Noun

先生せんせいだ → 先生せんせいだろう / 先生せんせいでしょう
Is a teacher → Is probably a teacher

Examples in Context

明日あしたは雨あめが降ふるでしょう。

Ashita wa ame ga furu deshō.

It will probably rain tomorrow.

Note: Polite prediction with high certainty


彼かれは来こないだろう。

Kare wa konai darō.

He probably won't come.

Note: Casual negative prediction


これは難むずかしいでしょう。

Kore wa muzukashii deshō.

This will probably be difficult.

Note: Polite prediction about difficulty

Seeking Confirmation with ~でしょう?

でしょう with a rising intonation can be used to seek confirmation:

美味おいしいでしょう?

Oishii deshō?

It's delicious, isn't it?

Note: Seeking confirmation about taste


東京とうきょうは大おおきい都市としでしょう?

Tōkyō wa ōkii toshi deshō?

Tokyo is a big city, isn't it?

Note: Seeking confirmation about known fact

Comparing Levels of Certainty

Expression Level of Certainty English Equivalent
かもしれない Low-Medium might, may, could be
だろう/でしょう Medium-High probably, likely
と思う/と思います Personal opinion I think, I believe

Cultural Note:
でしょう is versatile and can express varying degrees of certainty depending on context. It's often used in weather forecasts, predictions about future events, and in situations where the speaker has strong evidence but not absolute certainty. In formal writing like academic papers or news articles, でしょう is frequently used to present likely conclusions.

Explaining Reasons with 〜んです / 〜のです

To explain reasons or provide background information, Japanese uses 〜んです in casual spoken language and 〜のです in formal or written contexts. This structure clarifies your statements and gently explains why something is the case.

Formation

  • Verb (plain form) + んです / のです
  • い形容詞いけいようし + んです / のです
  • な形容詞なけいようし or noun + な + んです / のです

Present Verb

行いく → 行いくんです / 行いくのです
Go → The thing is, I'm going

Past Verb

行いった → 行いったんです / 行いったのです
Went → The thing is, I went

Present い-Adjective

高たかい → 高たかいんです / 高たかいのです
Expensive → The thing is, it's expensive

Present な-Adjective

元気げんきだ → 元気げんきなんです / 元気げんきなのです
Healthy → The thing is, they're healthy

Noun

学生がくせいだ → 学生がくせいなんです / 学生がくせいなのです
Is a student → The thing is, they're a student

Common Uses

1. Asking for explanations

どうして 遅れたおくれた んですか?

Dōshite okuretan desu ka?

Why were you late?


なぜ日本語にほんごを勉強べんきょうしているんですか?

Naze nihongo o benkyō shite irun desu ka?

Why are you studying Japanese?

Note: Question seeking explanation

2. Providing explanations or reasons

ちょっと 熱ねつ があるんです。

Chotto netsu ga arun desu.

I have a slight fever (that's why).


日本語にほんごを 勉強べんきょうしているんです。

Nihongo o benkyō shite irun desu.

I'm studying Japanese (that's why).

3. Adding background information

食たべたくないんです。
ダイエットだいえっと中ちゅうなんです。

Tabetakunain desu. Daietto chuu nan desu.

I don't want to eat. (It's because) I'm on a diet.


遅おそくなったんです。電車でんしゃが遅おくれたんです。

Osoku nattan desu. Densha ga okuretan desu.

I'm late. (It's because) the train was delayed.

Note: Explaining a situation with reason

4. Expressing discovery or realization

あ、財布さいふを忘わすれたんです!

A, saifu o wasuretan desu!

Oh, I've forgotten my wallet!

Note: Expressing a realization

Cultural Insight:
This explanatory form is often used to soften statements and provide context. It can also be used to confirm information, as in
"日本人にほんじんなんですか?"
meaning
"(Oh,) you're Japanese?"
This pattern helps create cohesion in conversation by connecting your statements to the context or to what was previously discussed, making Japanese dialogue feel more connected and thoughtful.

Combining Opinion and Explanation Patterns

Japanese allows you to combine different opinion and explanation patterns for more nuanced expression. These combinations help you articulate complex thoughts with appropriate levels of certainty, politeness, and context.

Common Combinations

1. 〜と思おもうんです / 〜と思おもうのです

Explaining the reason for your opinion or belief:

彼かれは忙いそがしいと思おもうんです。
いつも遅おそく帰かえりますから。

Kare wa isogashii to omoun desu. Itsumo osoku kaerimasu kara.

I think he's busy. Because he always comes home late.

Note: Explaining the reason for an opinion


この映画えいがは面白おもしろいと思おもうんです。
話はなしが良よいですから。

Kono eiga wa omoshiroi to omoun desu. Hanashi ga yoi desu kara.

I think this movie is interesting. Because the story is good.

Note: Explaining an opinion with a reason

2. 〜かもしれないと思おもいます

Expressing an opinion about a possibility:

明日あしたは雨あめが降ふるかもしれないと思います。

Ashita wa ame ga furu kamoshirenai to omoimasu.

I think it might rain tomorrow.

Note: Opinion about a possibility


彼かれは来こないかもしれないと思います。

Kare wa konai kamoshirenai to omoimasu.

I think he might not come.

Note: Opinion about a negative possibility

3.〜だろうと思おもいます

Stating your opinion about a probability:

テストは難むずかしいだろうと思います。

Tesuto wa muzukashii darō to omoimasu.

I think the test will probably be difficult.

Note: Opinion about a probability


彼女かのじょは合格ごうかくするでしょうと思います。

Kanojo wa gōkaku suru deshō to omoimasu.

I think she will probably pass.

Note: Opinion about a likely outcome

4. 〜かもしれないんです

Explaining about a possibility:

電車でんしゃが遅おくれるかもしれないんです。
だから、早はやく出でかけます。

Densha ga okureru kamoshirenain desu. Dakara, hayaku dekakemasu.

The train might be delayed. So I'm leaving early.

Note: Explaining a possibility as background information

Practical Usage:
These combinations are extremely useful in daily conversation, allowing for precise communication of complex thoughts. For example, in a business setting,
難むずかしいかもしれないと思おもいます
(I think it might be difficult) sounds more measured and thoughtful than a simple
難むずかしいです
(It's difficult).

Opinions and Possibility in Conversations

Let's examine how these patterns work together in natural conversations, highlighting how Japanese speakers express their thoughts with appropriate nuance, politeness, and context.

Dialogue: Discussing Weekend Plans

A: 週末しゅうまつ、何なにをしますか?
(Shūmatsu, nani o shimasu ka?)
"What are you doing this weekend?"

B: 天気てんきが良よければ、公園こうえんに行いこうと思おもいます。
(Tenki ga yokereba, kōen ni ikō to omoimasu.)
"If the weather is good, I think I'll go to the park."

A: 天気予報てんきよほうによると、雨あめが降ふるかもしれませんよ。
(Tenki yohō ni yoru to, ame ga furu kamoshiremasen yo.)
"According to the weather forecast, it might rain."

B: そうですか。雨あめが降ふるなら、
美術館びじゅつかんに行いくかもしれません。
(Sō desu ka. Ame ga furu nara, bijutsukan ni iku kamoshiremasen.)
"Is that so? If it rains, I might go to the museum."

A: 新あたらしい展示てんじがあるんですよ。
面白おもしろいと思おもいますよ。
(Atarashii tenji ga arun desu yo. Omoshiroi to omoimasu yo.)
"There's a new exhibition. I think it's interesting."

B: そうなんですか。では、美術館びじゅつかんに行いくことにします。
一緒いっしょに行いきませんか?
(Sō nan desu ka. Dewa, bijutsukan ni iku koto ni shimasu. Issho ni ikimasen ka?)
"Is that so? Then, I'll go to the museum. Would you like to go together?"

A: はい、行いきましょう。楽たのしいでしょうね。
(Hai, ikimashō. Tanoshii deshō ne.)
"Yes, let's go. It will probably be fun."

Dialogue: Discussing a Problem at Work

A: 山田やまださんはどうして会議かいぎに来こなかったんですか?
(Yamada-san wa dōshite kaigi ni konakattan desu ka?)
"Why didn't Mr. Yamada come to the meeting?"

B: 体調たいちょうが悪わるいんだと思おもいます。
昨日きのうから咳せきをしていました。
(Taichō ga waruin da to omoimasu. Kinō kara seki o shite imashita.)
"I think he's not feeling well. He's been coughing since yesterday."

A: そうですか。重おもい風邪かぜかもしれませんね。
(Sō desu ka. Omoi kaze kamoshiremasen ne.)
"I see. It might be a bad cold."

B: 明日あしたも来こないかもしれないんです。
大事だいじなプロジェクトがあるので、心配しんぱいなんです。
(Ashita mo konai kamoshirenain desu. Daiji na purojekuto ga aru node, shinpai nan desu.)
"He might not come tomorrow either. I'm worried because we have an important project."

A: 私わたしたちで何なにとかできるでしょう。
心配しんぱいしないでください。
(Watashitachi de nantoka dekiru deshō. Shinpai shinaide kudasai.)
"I think we can manage somehow. Please don't worry."

Dialogue: Giving Opinions About a Restaurant

A: この店みせのラーメンは美味おいしいと思おもいますか?
(Kono mise no rāmen wa oishii to omoimasu ka?)
"Do you think the ramen at this restaurant is delicious?"

B: はい、とても美味おいしいと思おもいます。
特とくにスープが好すきなんです。
(Hai, totemo oishii to omoimasu. Toku ni sūpu ga suki nan desu.)
"Yes, I think it's very delicious. I especially like the soup."

A: そうですか。少すこし塩辛しおからいかもしれないと思おもいましたが。
(Sō desu ka. Sukoshi shiokarai kamoshirenai to omoimashita ga.)
"Is that so? I thought it might be a bit too salty."

B: 人ひとによって好このみが違ちがうんですね。
次つぎは醤油しょうゆラーメンが良よいかもしれませんよ。塩辛しおからくないと思おもいます。
(Hito ni yotte konomi ga chigaun desu ne. Tsugi wa shōyu rāmen ga yoi kamoshiremasen yo. Shiokaraku nai to omoimasu.)
"People have different tastes, don't they? Next time, soy sauce ramen might be good. I don't think it's salty."

Cultural Note:
In Japanese conversation, opinions are often expressed tentatively out of politeness. Phrases like
と思おもいます
and
かもしれません
allow speakers to express their views without sounding too assertive. The explanatory form んです helps provide context and maintain the flow of conversation. These patterns work together to create a harmonious exchange of ideas while respecting different perspectives.

Practical Applications and Additional Examples

Let's explore more practical examples of how these opinion and possibility expressions are used in different contexts.

In Email Communication

先日せんじつお送おくりした資料しりょうについて
質問しつもんがあるかもしれないと思おもい、
ご連絡れんらくさせていただきました。

Senjitsu okuri shita shiryō ni tsuite shitsumon ga aru kamoshirenai to omoi, go-renraku sasete itadakimashita.

I'm contacting you because I thought you might have questions about the materials I sent the other day.

Note: Formal email expression combining possibility and opinion

In Academic Discussions

この研究けんきゅうの結果けっかによると、
新あたらしい治療法ちりょうほうが
効果的こうかてきだと言いえるでしょう。
しかし、さらなる研究けんきゅうが
必要ひつようかもしれません。

Kono kenkyū no kekka ni yoru to, atarashii chiryōhō ga kōkateki da to ieru deshō. Shikashi, saranaru kenkyū ga hitsuyō kamoshiremasen.

Based on the results of this research, we can probably say that the new treatment is effective. However, further research might be necessary.

Note: Academic discussion using probability and possibility expressions

In Daily Conversation

あの店みせに行いったんです。
すごく混こんでいたんです。でも、
料理りょうりは美味おいしかったと思おもいます。
今度こんど一緒いっしょに行いきませんか?

Ano mise ni ittan desu. Sugoku konde itan desu. Demo, ryōri wa oishikatta to omoimasu. Kondo issho ni ikimasen ka?

I went to that restaurant. It was really crowded. But I thought the food was delicious. Would you like to go together next time?

Note: Casual conversation using explanation and opinion patterns

In Business Settings

資料しりょうを確認かくにんしたところ、
売上うりあげは前年ぜんねんより増加ぞうかするでしょう。ただ、
競合きょうごうの新あたらしい製品せいひんの
影響えいきょうがあるかもしれないと思おもいます。

Shiryō o kakunin shita tokoro, uriage wa zennen yori zōka suru deshō. Tada, kyōgō no atarashii seihin no eikyō ga aru kamoshirenai to omoimasu.

After reviewing the materials, sales will probably increase compared to last year. However, I think there might be an impact from competitors' new products.

Note: Business discussion using probability and possibility expressions

Comparing Similar Expressions

雨あめが降ふると思おもいます
I think it will rain
Medium certainty - personal opinion

雨あめが降ふるかもしれない
It might rain
Low-Medium certainty - possibility

雨あめが降ふるでしょう
It will probably rain
Medium-High certainty - probability

雨あめが降ふるんです
It's going to rain (explanation)
High certainty - stating a fact with context/explanation

Practical Usage Tip:
When deciding which expression to use, consider:
How certain you are about the information
Whether you're expressing a personal opinion or a general probability
Whether you're providing background information or context
The level of politeness appropriate for the situation

Quick grammar reference

Want a focused, single-point recap of the grammar in this lesson? These reference pages explain each form on its own:

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