What it means
と思います expresses the speaker’s opinion or belief: “I think that...” It follows a plain-form clause and is polite because 思います is the polite form of 思う. With nouns and な-adjectives, use だ before と; with verbs and い-adjectives, use their plain form directly.
Usage note
In the basic pattern, the clause before と is normally in plain form, even when the whole sentence is polite. Do not use です or ます directly before と in patterns such as 学生だと思います or 行くと思います.
How to use it
あの人は先生だと思います。
I think that person is a teacher.
この町は静かだと思います。
I think this town is quiet.
このりんごは甘いと思います。
I think this apple is sweet.
明日は雨が降ると思います。
I think it will rain tomorrow.
あの人は先生だと思う。
I think that person is a teacher.
この町は静かだと思う。
I think this town is quiet.
このりんごは甘いと思う。
I think this apple is sweet.
明日は雨が降ると思う。
I think it will rain tomorrow.