とおもう

The expression とおもう is used to express your judgment or belief about something you think is true. It attaches after the plain form of verbs, or after adjectives and nouns in their appropriate forms. Use it when stating your opinion about a situation, a plan, or a belief. For nouns, you typically use だと思う (the だ is the copula). The nuance is that it conveys your own thought rather than a definite fact. In contrast, と思います is a more polite version. When describing immediate thoughts or uncertain guesses about the future, と思う can be used with mixed tones depending on context.