When talking about intention in Japanese, you can use two phrases: たい and と思う. However, they mean different things.

1. Want vs. Think

• たい is used when you really want to do something. For example, if you want to eat sushi, you would say 寿司が食べたい (sushi ga tabetai).
• と思う means "I think." You use it when you’re not quite sure about your desire. For instance, saying 行きたいと思う (ikitai to omou) means "I think I want to go." This shows you're thinking about it.

2. When to Use と思う

• When you're unsure: If you’re not sure if you really want something, you might say, 旅行に行きたいと思う (ryokou ni ikitai to omou), which means "I think I want to travel."
• When talking about plans with others: If you want to suggest something nicely, you would say 映画を見に行こうと思う (eiga o mi ni ikou to omou). This sounds friendlier than just saying you want to go.

Summary

In short, use たい when you have a strong desire and と思う when you’re thinking about something or being less direct, especially when talking with others.