思う is translated as to think in English. It's used to express personal feelings, opinions, beliefs, or judgments. Here are some simple sentences showing different ways 思う can be used. Note that 思う is used with the particle と in front of it.
| I think this movie is interesting. | この 映画 は 面白い と 思う。kono eiga wa omoshiroi to omou. |
| I believe that's correct. | それ は 正しい と 思う。sore wa tadashii to omou. |
| I think it will rain tomorrow. | 明日 は 雨 が 降る と 思う。ashita wa ame ga furu to omou. |
思う can also be used to express a decision that you've made.
| (I think) I've decided to buy this car. | この 車 を 買う と 思う。kono kuruma o kau to omou. |
| (I think) I've decided to wake up early tomorrow. | 明日、 早く 起きる と 思う。ashita, hayaku okiru to omou. |
Note that in these sentences, と 思う translates to something along the lines of I've decided or I intend, indicating that the speaker has made up their mind about the action. It can, however, still have an element of uncertainty, as decisions can change. It's a bit softer or more indirect than more definitive phrases using つもり.
