Examples
Meaning
〜たい means that the speaker wants to do an action. It attaches to the verb stem, so it is used for actions such as going, eating, studying, or sleeping.
Formation
Take the ます form of a verb and remove ます, then add たい. 行きます becomes 行きたい, 食べます becomes 食べたい, and 見ます becomes 見たい.
Usage
Use this pattern mainly for your own desire. It can also be used in questions to ask what someone wants to do, such as 何をしたいですか.
Nuance
〜たい is direct and personal. It is natural when talking about yourself, but when describing another person, Japanese often uses 〜たがる or reports what the person said.
Comparison
Use 〜たい for actions and 〜がほしい for things. 食べたい means you want to eat, while かばんがほしい means you want a bag.
Common Mistakes
A common mistake is attaching たい to the dictionary form. Say 行きたい, not 行くたい. Learners also sometimes forget that 〜たい behaves like an い-adjective, so the negative form is 〜たくない.
Related Grammar
〜がほしい
〜がほしい (ga hoshii) means that you want something. It is used for nouns, not for actions.
〜てほしい
〜てほしい (te hoshii) is used when you want someone else to do something. It expresses your wish about another person's action.
〜たがる・〜ほしがる
〜たがる and 〜ほしがる are used to describe another person's desire from the outside. They are useful when talking about what someone seems to want.
〜ようと思う
〜ようと思う (you to omou) expresses that you are thinking of doing something or have an intention to do it. It is softer than a firm plan.