かもしれない

かもしれない expresses a guess or speculation about something that is not certain. It softens statements, making them less definite than です/だろう. Use it when you have some evidence or probability but nothing is confirmed. It can be used for present or future events. For negative speculation, use 〜ないかもしれない. The nuance is roughly equivalent to 'may', 'might', or 'probably' in English, depending on context and likelihood.