Can and can't - English grammar exercises

Write sentences.
  positive:
  Catherine and Ann 4 songs. (to sing)
  Jake a book. (to read)
  Amy her friend. (to meet)
  Our family England. (to visit)
  negative:
  John a bike. (to ride)
  I this tree. (to climb)
  They 10 pounds. (to change)
  Our class everything. (to understand)