41. He hasn’t played the guitar for ten years

S have/has(not) VPII for...
42. We haven’t met each other for two weeks
43. It’s a month since they last told jokes to the children 
44. It’s four years since Hoa last took an exam
45. I have never known what a credit card is before
46. The baby has never seen an elephant before
47. This is the first time she has eaten vegetarian food
48. This is the first time the children have enjoyed swimming in a water park
49. Basketball has been played by Tom since he entered university 
50. His friends haven’t been given Minh’s old books since he moved to Cu Chi
51. His bike hasn’t been ridden by Ba for three months 

S have/has(not) been VPII for ...