"I have a plan to" implies more complexity. You want to resolve an issue, and you've decided on a solution. The other two are interchangeable. You're simply announcing your intention to do something.

Hi there! Great question! Let's break down the meaning and usage of each sentence: "I have a plan to 〇〇" This sentence means you possess a specific plan or idea to do something. It emphasizes having a concrete plan. "I am planning to 〇〇" This sentence means you are in the process of making arrangements or preparations to do something. It emphasizes ongoing planning. "I plan to 〇〇" This sentence means you intend or expect to do something in the future. It is a straightforward statement of intention. Do they mean the same thing? Yes, they all convey a similar intention of doing something, but with slight differences in emphasis: "I have a plan to" stresses possessing a specific plan. "I am planning to" stresses the process of planning. "I plan to" stresses the intention to do something. Which one is the most commonly used? "I plan to 〇〇" is the most commonly used in everyday conversation because it is simple and direct.