ものと思う
Think that, Believe that, Expect that, Have confidence that, Absolutely
Structure
［い］Adjective + ものと思う
［な］Adjective + な + ものと思う
Noun + な + ものと思う
Explanation
物と思う is formed by combining the noun 物 'thing', the case marking particle と, and the う-Verb 思う 'to think'. This expression is typically translated as 'to be convinced that (A)', or 'to firmly believe that (A)'. More broadly, this grammar point leverages one of the nuances of 物 to frame an abstract idea or assumption as something the speaker confidently holds to be a concrete fact.
Because もの functions as a noun, this pattern can be preceded by any word in its attributive form.
- 有名な大学に入ったから、彼はきっと頭がいいものと思っていたが、話してみるとそうでもなかった。He got into a famous university, so I was convinced he was smart, but after talking with him, that wasn't really the case.
- 有名なレストランだから、料理は全部おいしいものと思っていたけど、がっかりした。Because it's a famous restaurant, I took it for granted that all the food would be delicious, but I was disappointed.
- ペットを飼うことは、大変だが楽しいものと思う人がほとんどだろう。Most people probably believe that having a pet, while a lot of work, is an enjoyable thing.
- オーストラリアの首都はシドニーであるものと思っている人が多いが、正しくはキャンベラだ。Many people are under the assumption that the capital of Australia is Sydney, but it's actually Canberra.
Using the past tense form, ものと思っていた, often implies that the speaker's belief turned out to be incorrect. Common translations in this case are 'I had assumed that (A)', or 'I was under the impression that (A)'.
- 子供はみんなアニメが好きなものと思っていたが、うちの子は全く興味がないらしい。I had assumed that all children like anime, but it appears my kid has no interest in it whatsoever.
While this expression carries a somewhat formal tone, it is not uncommon to hear it in everyday conversations.
Examples
医者が患者に：「この<新しい薬で症状は必ず改善されるものと<思います。」
Doctor to a patient: 'I am confident that your symptoms will improve with this new medication.'
警察の発表：「犯人はまだこの地域内に潜伏しているものと<思われます。」
Police announcement: 'It is believed that the culprit is still hiding within this area.'
私たちの新しいプロジェクトは、必ず成功するものと<思っています。
I firmly believe that our new project will be a success.
田中さんはこの仕事の適任者であるものと<思いますが、本人の意向も確認しましょう。
I think that Mr. Tanaka is the right person for this job, but let's confirm his intentions as well.
古代の人々は、現代の私たちには想像もできないほど過酷な生活を送っていたものと<思う。
I imagine that people in ancient times lived lives that were harsh beyond our modern imagination.
監督から選手へ：「君なら、きっとこの試合で活躍できるものと<思っている。」
Coach to a player: 'I have every confidence that you will perform well in this match.'
あの店はいつも行列ができているから、料理はかなり美味しいものと<思う。
There's always a line at that restaurant, so I assume that the food is quite delicious.
彼は昨日、遅くまで残業していたものと<思う。今日はとても疲れているようだ。
I figure that he worked overtime until late yesterday. He looks very tired today.
けんた：「このゲーム、クリアできるかな？」
ゆうき：「たぶん、なんとかなるもんと<思うよ。」
Kenta: 'Do you think we can beat this game?'
Yuuki: 'I think we'll probably manage somehow.'
彼の提案は、会社全体にとって有益なものと<思います。
I believe that his proposal will be beneficial for the entire company.
次の電車は間もなく到着するものと<思いますので、白線の内側でお待ちください。
We expect that the next train will be arriving shortly, so please wait inside the white line.
サプライズプレゼントを受け取った彼女は、さぞ喜んでいるものと<思います。
Having received the surprise present, I am sure that she must be absolutely delighted.