A prediction describes an expected event; a plan describes an intended action. "The train may be crowded because there is a concert tonight" predicts a condition. "I am going to take an earlier train" states your response.
Connect the prediction to evidence you actually have. In a fictional timetable exercise, you might say, "Only two evening services are listed, so I expect the later one to be busy." The timetable supports a reason for concern, but it does not prove how many passengers will travel.
Match certainty to the situation
Compare "It might be busy," "It will probably be busy," and "It is definitely full." The last statement requires stronger evidence, such as a reliable current booking status for a service where that information is relevant.
Ask a partner to challenge one assumption: "What if most concertgoers drive?" You can respond, "That is possible. I am taking the earlier train as a precaution, not because I know the later one is full."
Practice another prediction about a class event or a deadline, avoiding high-stakes claims outside your knowledge. State what new information would change your expectation. This develops useful future language alongside careful reasoning: listeners should be able to distinguish the evidence, your interpretation, and the action you choose in response.