My general perspective on Leadership is that everyone has an opportunity to showcase it in different forms throughout their lifetime - both formally and informally. If your question is with respect to listing out the times that you've shown leadership in the past, as part of a job application or resume building activity, I would encourage you to think about the following:
- Are there times that you've organized or helped plan and deliver an event for your school? (a party, a dance, a student organization or event)
- Have you organized or help coach in local sports club or team?
- Have you taken on responsibility for helping to care for other family members (younger or older)?
- Have you helped lead or organize events for your local town or community, or a local religious organization?
Any time you help bring people together to accomplish something, or take on responsibility to get something done (even if you're the only one involved) - that's a form of leadership.
I would encourage you to think about school projects, team activities, extracurricular opportunities where perhaps you played a dominant role in a decision or assisted a peer or teammate in a way that developed your leadership skills. Sometimes thinking back to a situation may enable you to get a different perspective of it.