modality N1 uncommon writtenpolite
〜ものと思う — to assume / take it for granted that ~
〜ものと思う
Builds on もの
Meaning
- to assume ~ / take it for granted that ~ — hold something as a natural, settled belief rather than a tentative guess
Inserting もの before と思う frames the belief as something self-evident or expected-as-a-matter-of-course, not a mere opinion. 締め切りは守るものと思っていた ('I took it for granted that deadlines are kept'). The もの lends the assumption the air of common sense or a default expectation — firmer and more impersonal than the everyday と思う.
Key sentence
全員が出席するものと思っています。
I'm assuming everyone will attend.
Formation
| Attaches to | Form | Example |
|---|---|---|
| Verb / adjective (plain); Noun + である | V/A(plain) + ものと思う | 来る → 来るものと思う |
When: Formal-leaning; states a default assumption the speaker holds, often about what should naturally be the case.
Examples
返事がないので、承知したものと思います。
Since there's no reply, I'll assume you've agreed.
彼なら当然賛成するものと思っていた。
I'd assumed that he, of all people, would naturally agree.
Easily confused with
〜と思う Plain と思う is 'I think ~', a personal opinion or guess; ものと思う frames it as a *taken-for-granted assumption* — what one expects to be naturally the case. 〜ものと思っていた ものと思う states a present assumption; the past ものと思っていた typically reveals it was *mistaken* ('I had assumed ~, but actually …'). 〜ものと思われる ものと思う is the speaker's own assumption (active); ものと思われる is the impersonal passive 'it is presumed', presenting it as a general/objective inference.
Notes
- Closely related to はずだ (deduction from evidence); ものと思う is more about a default expectation or common-sense assumption than a reasoned conclusion.
See 〜ものと思う in real sentences
Jengo shows 〜ものと思う the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled from published Japanese grammar references.