4. (+) Jim has just played video games with his brother.
(-) Jim hasn't just played video games with his brother
(?). has jim  just played video games with his brother ?
5. (+). My grandmother has visited me since November.
(-) My grandmother hasn't visited me since November.
(?).has your grandmother visited you since November.
6. (+). your sisterhas  studied medicine for 2 years
(-). your sister hasn't  studied medicine for 2 years
(?) Has your sister studied medicine for 2 years?
7. (+) It has been long since our last encounter.
(-). It hasn't been long since our last encounter.
(-)We haven't graduated yet.