Помогите пожалуйста ничего не понимаю...

Tom is playing basketball at the moment. Pr. Continues Tom plays… Pr. Simple My friends are going… Pr. Continues My friends go… Pr. Simple I visit my… Pr. Simple My parents and I have been living… Pr. Perfect Continues I'm visiting… Pr. Continues I know Fred for 3 years. Pr. Simple I'm watching… Pr. Continues I watch… Pr. Simple I have watched… Pr. Perfect