Basic Japanese Grammar: I Think… (と思う)

Published January 14th, 2022

Our Nihongo Master Podcast has a language series called Study Saturday, where a Japanese grammar point is introduced in a fun, easy, and bite-sized way. In Season 2 Episode 8, we looked at how to express our opinions with the phrase “I think”.

This grammar point is part of basic Japanese and is used pretty frequently in everyday conversation. It makes your sentence a bit less serious as well. The best part about this grammar point is that it’s so easy to learn! There’s only one phrase in Japanese that is used to express your opinion.

In the podcast episode, not only did we discuss a bit about the grammar point, but we also had a few roleplaying scenarios using the new grammar to get listeners accustomed to it. The roleplaying scenarios are not in this recap, so you’ve got to tune in to listen!

Grammar Point

Expressing opinions is crucial in any language. In Japanese, it’s also used to make the tone of the sentence lighter. The grammar to use to say this is pretty simple: you basically just add “to omou” (と思う) or “to omoimasu” (と思います) for the polite form, to the end of any sentence. And viola, that’s it!

Quick and easy, right?

と思う for i-adjectives and verbs

Let’s have an example. Say you saw someone and thought he was cool: “I thought he was cool”. “Cool” in Japanese is kakkoii (かっこいい). We could say “kakkoii to omou” (かっこいいと思う), but that translates to “I think he is cool”. To make it so it means “I thought he was cool”, we have to change the grammar point we just learned to the past tense. “to omou” ends with an u, so it conjugates to “to omotta” (と思った) for the casual form. For the polite form, simply change the “masu” (ます) to past tense to get “to omoimashita” (と思いました).

Now put it all together and we get: “kare ha kakkoii to omotta”(彼はかっこいいと思った). For the polite form, it’s “kare ha kakkoii to omoimashita” (彼はかっこいいと思いました).

Kakkoii is an i-adjective, so there’s no change whatsoever when attaching the grammar phrase at the end. It’s the same when the word that comes before the phrase is a verb, like the sentence “I think we went to a cafe”. “Went” in Japanese is “itta” (行った), the past tense of the word “iku” (行く). All you have to do is have all the pieces and just add the grammar at the end: “kafe ni itta to omou” (カフェに行ったと思う). For the polite form, it’s “kafe ni itta to omoimasu” (カフェに行ったと思います).

だと思う for na-adjectives and nouns

The time you do need to add something on is when the word before is either a noun or a na- adjective. In the sentence “He thought I was beautiful”, the word that comes right before the grammar phrase is “beautiful”, and that’s the na-adjective “kireina” (綺麗な) in Japanese. We can’t say “kireina to omou”, but instead we take the na out and switch it to da, the casual form of desu: “kare ha watashi ga kirei da to omotta” (彼は私が綺麗だと思った). For the polite form, it’s “kare ha watashi ga kirei da to omoimashita” (彼は私が綺麗だと思いました). Remember, that sentence was in the past tense.

Let’s have an example for a noun. Since there is no “na” to switch out, we just add da in between the noun and “to omou”. For example, if you want to say “I think he’s Japanese”, you can say it as “kare ha nihonjin da to omou” (彼は日本人だと思う). The polite form of the sentence is “kare ha nihonjin da to omoimasu” (彼は日本人だと思います).

Negation

In the case where you want to have a na-adjective or a noun in the negative form, like “I think he’s not Japanese” or “I think she’s not beautiful”, their negative form “janai” (じゃない) then acts like an i- adjective, so you don’t need to have a “da” in between: “nihonjin janai to omou” (日本人じゃないと思う), “kirei janai to omou” (綺麗じゃないと思う).

One last thing: if you want to say “i don’t think”, all you have to do is say the negation of “to omou”, which is “to omowanai” (と思わない) or “to omoimasen” (と思いません). So let’s switch “I think he’s not Japanese” to “I don’t think he’s Japanese” — we take the noun as it is and add the negation of the grammar to make, “nihonjin da to omowanai” (日本人だと思わない), or the polite form “nihonjin da to omoimasen” (日本人だと思いません).

Vocab Recap

As always, let’s have a quick vocab recap to wrap it up:

Kakkoii (かっこいい) — cool

Kireina (綺麗な) — beautiful or pretty

Isha (医者) — doctor

Shokugyō (職業) — occupation

Gaka (画家) — painter

Machigainai (間違いない) — undoubtedly or no doubt

Ginkõ (銀行) — bank

Hataraiteiru (働いている) — to be working

Kaku (書く) — to write or draw

Shou ga nai (しょうがない) — it can’t be helped

Muzukashii (難しい) — difficult

Mirai (未来) — future

Hiraku (開く) — to open

Sasuga (さすが) — as expected

Hazukashii (恥ずかしい) — shy

Shinyū (親友) — best friend

Kareshi (彼氏) — boyfriend

Urayamashii (羨ましい) — jealous

Zettai (絶対) — definitely

Conclusion

And that’s the recap of this episode of Study Saturday, and that means you might already be an expert at expressing your opinions in Japanese. I, for one, have a lot of opinions on a lot of things, so rest assured I’ve been using this every day — if not every hour. Since this article is a recap, head over to the original episode to listen to the full thing now!

If you’re interested in similar bite-sized grammar pointers, head over to the Nihongo Master Podcast for more. The Study Saturday language series comes out every Saturday with a new grammar point with examples and role playing scenarios. Click here for your fill of basic Japanese grammar!